Sports activity after short-stem hip arthroplasty

Return to Sports and Recreational Activities Following Arthroplasty of the Basal Joint of the Thumb: A Retrospective Review

Purpose

Arthroplasty of the basal, or carpometacarpal, joint of the thumb has been shown to decrease pain, improve strength, improve range of motion, and allow return to work. This study sought to assess whether basal joint arthroplasty also allows for a return to sports and recreational activities.

Methods

A survey assessing participation in sports and recreational activities, timing of return to play after surgery, enjoyment, and the presence of pain and limitations was mailed to patients who had undergone an arthroplasty of the basal joint of the thumb over a 3-year period.

Results

Of the 333 patients who underwent thumb carpometacarpal arthroplasty, met the criteria, and responded, 73% were able to successfully return to sports and recreational activities, with decreased pain and at the same or increased level of play, frequency of participation, and level of enjoyment for their sport or recreational activity. Patients were more likely to successfully return to sports and recreational activities if they had undergone surgery on their nondominant hand, did not stop their sport or recreational activity before surgery, were able to return within 9 months of surgery, and reported no postoperative limitations. Successful return to sports and recreational activities was not related to age, sex, surgeon, level of play, or the type of sport or recreational activity.

Conclusions

Most patients who replied to our survey reported successful return to sports and recreational activities after arthroplasty of the basal joint of the thumb.

Type of study/level of evidence

Prognostic IV.

Gender equality challenges in orthopaedic surgery: a systematic review

PURPOSE

Several studies have examined gender-equality challenges and ways to improve women's representation and management. Orthopaedic surgeons and patients are less gender equitable than them of other surgical disciplines. This systematic review summarizes these findings and highlights orthopaedic surgery gender inequality.

METHODS

Search of the PubMed, Embase, and Cochrane databases was carried out to extract human studies investigating the gender gap in orthopaedics, trying to highlight the equality challenges orthopaedic surgery faces. Studies incorporating patients with comorbidities in which gender is a proven risk factor, and pregnant women were excluded.

RESULTS

This systematic review included 59 studies involving 692,435 people (mean females/males ratio: 4.44), spanning the years 1987-2023. Regarding the targeted population, 35 (59.32%) studies focused on patients, while 24 (40.68%) on physicians. Orthopaedic surgery is described as an unfriendly career field for women as surgeons or sports leading physicians while women are generally under represented in the academic field of orthopaedics. Regarding patients, female gender consists both a risk and prognostic factor influencing the prevalence of degenerative disease and the outcome of the operative treatment in reconstructive orthopaedics. Female gender is a risk factor for multiple sports injuries and influences the pathogenetic mechanisms resulting in ACL reconstruction. Regarding spine surgery, women are less likely to have surgery suggested, and such suggestion underlines severe disease's progression.

CONCLUSIONS

Gender differences affect orthopaedic patient-physician-healthcare system interactions. Recognizing biases and their patterns is useful to improve the actual situation. By preventing those an unbiased, tolerant, and egalitarian workplace for physicians and a healthcare system that provides the best treatment to patients could be created.

Reverse dynamics analysis of contact force and muscle activities during the golf swing after total hip arthroplasty

There are no reports on hip kinetics including contact forces and muscle activities during the golf swing after total hip arthroplasty (THA). The aim of this study was to identify the characteristics of three-dimensional dynamics during the golf swing. Ten unilateral primary THA patients participated in motion capture test of their driver golf swing. The driver swing produced approximately 20-30° of rotation in both lead and trail replaced hips. The mean hip contact forces (HCFs) of lead and trail replaced hips were 5.1 and 6.6 × body weight, respectively. Left and right THAs showed similar HCFs of lead and trail hips. More than 60% of the Percent maximum voluntary isometric contraction was found in bilateral iliopsoas muscles in all unilateral THA. Three factors [female sex, lower modified Harris Hip Score, and higher HCF of surgical side] were associated with the golf-related replacement hip pain. Golf is an admissible sport after THA because driver swings do not contribute excessive rotation or contact forces to hip prostheses. HCF could be reduced through swing adjustments, which may allow patients with golf-related replacement hip pain to develop a comfortable golf game free from pain.

Similar results after five years with the use of the Fitmore or the CLS femoral components

Although the Fitmore Hip Stem has been on the market for almost 15 years, it is still not well documented in randomized controlled trials. This study compares the Fitmore stem with the CementLeSs (CLS) in several different clinical and radiological aspects. The hypothesis is that there will be no difference in outcome between stems. In total, 44 patients with bilateral hip osteoarthritis were recruited from the outpatient clinic at a single tertiary orthopaedic centre. The patients were operated with bilateral one-stage total hip arthroplasty. The most painful hip was randomized to either Fitmore or CLS femoral component; the second hip was operated with the femoral component not used on the first side. Patients were evaluated at three and six months and at one, two, and five years postoperatively with patient-reported outcome measures, radiostereometric analysis, dual-energy X-ray absorptiometry, and conventional radiography. A total of 39 patients attended the follow-up visit at two years (primary outcome) and 35 patients at five years. The primary outcome was which hip the patient considered to have the best function at two years. At two and five years, more patients considered the hip with the CLS femoral component as superior but without a statistically significant difference. There were no differences in clinical outcome, magnitude of femoral component migration, or change of bone mineral density at five years. At three months, the Fitmore femoral component had subsided a median -0.71 mm (interquartile range (IQR) -1.67 to -0.20) and the CLS femoral component -0.70 mm (IQR -1.53 to -0.17; p = 0.742). In both groups the femoral head centre had migrated posteriorly (Fitmore -0.17 mm (IQR -0.98 to -0.04) and CLS -0.23 mm (IQR -0.87 to 0.07; p = 0.936)). After three months neither of the femoral components showed much further migration. During the first postoperative year, one Fitmore femoral component was revised due to aseptic loosening. Up to five years, we found no statistically significant difference in outcomes between the Fitmore and the CLS femoral components. The slightly worse outcomes, including one revised hip because of loosening, speaks against the hypothesis that the Fitmore femoral component should be advantageous compared to the CLS if more patients had been recruited to this study.

Time for return to sport following total hip arthroplasty: a meta-analysis

INTRODUCTION

Total Hip Arthroplasty (THA) is being increasingly undertaken in younger and more active patients, with many of these patients wanting to return to sport (RTS) after surgery. However, the percentage of patients RTS and time at which they are able to get back to sport following surgery remains unknown. The objective of this meta-analysis was to determine the time patients RTS after THA.

METHODS

A search was performed on PUBMED, MEDLINE, EMBASE, and the Cochrane Library for trials on THA and RTS, in the English language, published from the inception of the database to October 2020. All clinical trials reporting on to RTS following THA were included. Data relating to patient demographics, methodological quality, RTS, clinical outcomes and complications were recorded. The PRISMA guidelines were used to undertake this study.

RESULTS

The initial literature search identified 1720 studies. Of these, 11 studies with 2297 patients matched the inclusion criteria. 3 studies with 154 patients demonstrated an overall pooled proportion of 40.0% (95% CI, 32.5-47.9%) of patients RTS between 2 and 3 months after surgery. 4 studies with 242 patients demonstrated an overall pooled proportion of 76.9% (95% CI, 71.5-82.0) of patients RTS by 6 months after surgery. Pooled proportion analysis from 7 trials with 560 patients demonstrated 93.9% (95% CI, 82.7-99.5%) of patients RTS between 6 and 12 months after surgery.

CONCLUSIONS

Pooled proportion analysis showed increasingly more patients were able to RTS after THA over the first 1 year after surgery. There remains marked inter and intra-study variations in time for RTS but the pooled analysis shows that over 90% of patients were able to RTS at 6-12 months after THA. These finding will enable more informed discussions between patients and healthcare professionals about time for RTS following THA.

Factors affecting sports participation after total hip arthroplasty

PURPOSE

The purpose of this study was to investigate the rate of return to sports after total hip arthroplasty (THA) in patients who regularly participate in sports and evaluate the factors that can affect the return to sports.

METHODS

In total, 165 patients who had been continuously participating in sports prior to surgery were included from a total of 401 patients who underwent THA from 2015 to 2018. The mean follow-up was 3.3 (range, 2-6) years. Demographics, medical history, surgical parameters, functional outcomes, and anxiety about complications at the final follow-up were compared between the patients who participated in the same sports as before surgery (S group) and those who could not (N group).

RESULTS

The overall return to sports rate was 79% for 68 (41%) and 97 (59%) patients in the S and N groups, respectively. The most common sports that patients participated in post-operatively were walking (76 patients, 46%) and swimming (37 patients, 22%), followed by muscle training (25 patients, 15%). There were significant differences between the groups in the following patient factors: sex, primary disease, post-operative Japanese Orthopedic Association Hip-Disease Evaluation Questionnaire outcome, and anxiety about falls and dislocation. In the evaluation of factors affecting return to sports using logistic regression analysis, male sex (odds ratio 3.66, 95% confidence interval 1.13-11.19, p = 0.029) and anxiety of dislocation (odds ratio 3.42, 95% confidence interval 1.58-7.42, p < 0.01) were extracted as independent risk factors.

CONCLUSION

Careful patient guidance and rehabilitation, in addition to accurate surgical procedures, will improve patient participation in sports.

Recreational activity after open hip abductor repair

BACKGROUND

Hip abductor tear (HAT) is an increasingly diagnosed cause of refractory lateral hip pain and dysfunction, affecting 10-25% of the general population.

PURPOSE

(1) to determine the rate of return to activity and to assess the physical and recreational activity of patients undergoing open hip abductor repair (oHATr) and (2) to describe the modification or initiation of new sports disciplines.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 28 patients (29 hips) who underwent an oHATr were prospectively analyzed at a midterm follow-up of 3.5 (range 2-5) years. The sports and recreational activity levels, as well as type of sports practiced before and after surgery, and The Veterans RAND 12 Item Health Survey (VR-12) were assessed via questionnaire.

RESULTS

At the final follow-up, all patients were active in sports after surgery. The duration and frequency of sports activities showed a slight decrease (48-42 min per week and 3.2-2.9 sessions per week, respectively) (p = 0.412 and 0.135, respectively). The VR-12 had a score of 45 (13.12-63.18) points for the physical component and 41 (32-53.8) points for the mental component. 100% of the patients would undergo the surgery again. 95% of patients were satisfied with the overall results of the surgical outcome, with 98% satisfied with their hip pain relief and ability to undertake daily and work activities. Moreover, 94% were satisfied with their ability to return to recreational activities. The failure rate in our cohort was approximately 14%.

CONCLUSION

All patients who underwent an oHATr were able to return at least to one type of sport. This cohort was highly satisfied with their sports involvement and recreational activity achievement. In addition, 88% of patients reported that oHATr improved sports activity. There was a shift from higher to lower impact sports. Furthermore, just 3 hips present a retear after surgery.

Overstretching Expectations May Endanger the Success of the “Millennium Surgery”

Total hip arthroplasty (THA) is an extremely successful treatment strategy. Patient expectations, however, have increased; if not properly guided by surgeons, at present, patients expect next to pain-free restoration of the joint and a fast return to work and sports. While the revision rates after THA also increased in younger patients, knowledge on musculoskeletal loads still remains sparse, and the current recommendations on postoperative rehabilitation are based on expert opinions only. The aim of this study was to unravel biomechanical contact conditions in “working age” (&lt;60 years, 53.5 ± 3.0 years) and “retirement age” (&gt;60 years, 67.7 ± 8.6 years) patients during activities recommended post-THA. We hypothesized that working age patients would show substantially increased hip contact loads compared to older patients. The in vivo joint contact force (Fres) and torsion torque (Mtors), reflecting the main contact load situation, experienced during activities of daily living and sports activities were measured in a unique group of 16 patients with instrumented THA. We summarized patient activities and sports recommendations after THA mentioned within the literature using PubMed (without claim of completeness). The measurements showed that younger working age patients experienced significant (p = 0.050) increased Mtors (21.52 ± 9.11 Nm) than older retirement age patients (13.99 ± 7.89 Nm) by walking. Bowling, as a recommended low-impact sport, was associated with Fres of up to 5436 N and Mtors of up to 108 Nm in the working age group, which were higher than the Fres (5276 N) and Mtors (71 Nm) during high-impact soccer. Based on our results, age was proven to be a discriminator in joint loading, with working age patients presenting with increased loads compared to retirement age patients, already during daily activities. The current patient recommendations have led to further increased joint loadings. If THA cannot be delayed in a patient, we propose counselling patients on a carefully considered return to sports, focusing on low-impact activities, as indicated hereby. The findings from this work illustrate the need to provide critical feedback to patient expectations when returning to work and sports activities. Patients returning to more intensive sports activities should be carefully monitored and advised to avoid as much overloading as possible.

Clinical and radiographic outcomes after total hip arthroplasty with the NANOS neck preserving hip stem: a 10 to 16-year follow-up study

BACKGROUND

Short-stem Hip Arthroplasty (SHA) are increasingly implanted in recent years thanks to their potential advantage in preserving metaphyseal bone-stock. Among them, the NANOS® short-stem implant demonstrated satisfactory results to short and mid-term. The purpose of this retrospective study was to evaluate the clinical and radiographic outcome of the Nanos® short stem at a minimum follow-up of 10 years.

METHODS

Sixty-seven patients aged 53 ± 20 years were enlisted in the study, for a total of 72 hips. Primary outcomes were survivorship of the implant and clinical outcome measured using the Hip disability and Osteoarthritis Outcome scores (HOOS) and the Short Form Survey (SF12) questionnaire. The secondary outcome was a radiological evaluation calculating the inclination and the anteversion angle of the acetabular cup for each implant and investigating osteolysis, heterotopic ossifications and stem position.

RESULTS

We observed a 95.5% stem survivorship. The complication rate was 7.6% and three implants underwent revision because of an aseptic loosening, an infection and a periprosthetic fracture due to trauma. Among 58 patients (63 hips) evaluated in an outpatient visit 10-16 years after surgery, improvement in clinically relevant scores comparing with baseline was observed: HOOS score increased after surgery in all its subcategories (from 32.25 ± 14.07% up to 91.91 ± 9.13%) as well as SF12 which increased by more than 18 percentage points. On clinical assessment, the range of motion (ROM) was restored at follow-up, 1 patient (1.7%) showed a squeaking hip and 2 (3.4%) reported leg-length discrepancy. Neutral stem positioning was achieved in 58 hips and heterotopic ossifications occurred in 10 hips (16%).

CONCLUSIONS

The current study reports good clinical and radiological outcomes following NANOS® short-stem hip implant at minimum 10 years-follow-up. Since the high rate of stem survivorship, the low complication rate demonstrated and the overall patient satisfaction, our results suggest NANOS® neck-preserving prostheses should be considered as a valid alternative to standard implants.

Recreational activity after cementless total hip arthroplasty in patients older than 75 years

INTRODUCTION

This retrospective study aimed to compare activity levels before and at mid-term follow-up after primary cementless total hip arthroplasty (THA) in patients older than 75 years.

MATERIALS AND METHODS

A cohort of 79 patients with a mean age at surgery of 78 years (range 76-84 years) was evaluated 6.3 years (range 4-8 years) after cementless THA due to osteoarthritis and was followed up with a questionnaire to determine their activity level. Pre- and post-operative recreational activities were assessed at routine follow-up using the University of California, Los Angeles activity score, and the Schulthess Clinic sports and activity questionnaire. Post-operative health-related quality of life was measured using Veterans Rand 12-item survey (VR-12).

RESULTS

Six years after THA, 72% of preoperatively active patients had returned to activity. Comparing activity preoperatively (before the onset of symptoms) and 6 years after THA, the number of disciplines and session length has decreased significantly. A significant decline in high-impact activities was observed, while participation in low-impact activities significantly increased.

CONCLUSION

The majority of patients maintained a recreational activity level in the mid-term after primary cementless THA. However, a change in disciplines toward low-impact activities was observed.

Amount and type of physical activity and sports from one year forward after hip or knee arthroplasty-A systematic review

INTRODUCTION

After rehabilitation following total hip or knee arthroplasty (THA/TKA), patients are advised to participate in physical activity (PA) and sports. However, profound insight into whether people adopt a physically active lifestyle is lacking. Aim is to gain insight into the performed amount and type of PA (including sports) and time spent sedentarily by persons after THA/TKA.

METHODS

A systematic review (PROSPERO: CRD42020178556). Pubmed, Cinahl, EMBASE and PsycInfo were systematically searched for articles reporting on amount of PA, and on the kind of activities performed between January 1995-January 2021. Quality of the articles was assessed with the adapted tool from Borghouts et al.

RESULTS

The search retrieved 5029 articles, leading to inclusion of 125 articles reporting data of 123 groups; 53 articles reported on subjects post-THA, 16 on post-hip-resurfacing arthroplasty, 40 on post-TKA, 15 on post-unicompartimental knee arthroplasty and 12 on a mix of arthroplasty types. With respect to quality assessment, 14 articles (11%) met three or fewer criteria, 29 (24%) met four, 32 (26%) met five, 42 (34%) met six, and 6 (5%) met seven out of the eight criteria. PA levels were comparable for THA and TKA, showing a low to moderately active population. Time spent was mostly of low intensity. Roughly 50% of -subjects met health-enhancing PA guidelines. They spent the largest part of their day sedentarily. Sports participation was relatively high (rates above 70%). Most participation was in low-impact sports at a recreational level. Roughly speaking, participants were engaged in sports 3 hours/week, consisting of about three 1-hour sessions.

CONCLUSION

Activity levels seem to be low; less than half of them seemed to perform the advised amount of PA following health-enhancing guidelines Sports participation levels were high. However, many articles were unclear about the definition of sports participation, which could have led to overestimation.

Sports Activity and Patient-Related Outcomes after Cementless Total Hip Arthroplasty in Patients Younger than 40 Years

BACKGROUND

The management of degenerative hip diseases in young patients remains a challenge. Despite the improvement of hip-preserving procedures, total hip arthroplasty (THA) may be required in some instances. In addition, young patients undergoing THA have high expectations concerning their postoperative level of activity.

PURPOSE

(1) to define the sports activity level and the return to sports after THA, (2) to describe the modification or initiation of new sports disciplines, and (3) to report the clinically meaningful outcomes after THA in patients younger than 40 years.

METHODS

A total of 36 patients (40 hips) were prospectively analyzed at a midterm follow-up of 3.9 years. The modified Harris Hip Score (mHHS); the Visual Analog Scale (VAS) for pain; the University of California, Los Angeles (UCLA) activity scale; and sports and recreational activity levels were assessed via questionnaire. The minimal clinically important difference (MCID) was determined by calculating half of the standard deviation, and the substantial clinical benefit (SCB) as well as patient acceptable symptomatic state (PASS), were calculated by the anchor method for the mHHS.

RESULTS

At the final follow-up, there was a significant improvement in mHHS (34.1 to 92.6; p < 0.0001), UCLA (3.2 to 7.6; p < 0.0001), and VAS for pain (8 to 1; p < 0.0001). More patients were active in sports at follow-up than before surgery (44% to 92%, p < 0.0001). In addition, the duration and frequency of sports activities showed a significant increase (p < 0.0001). The MCID, SCB and PASS for mHHS were 89% and 58%, respectively. No revision surgery had to be performed.

CONCLUSION

This study showed that a large proportion of patients under 40 years of age who underwent THA increased their physical activity. Eighty-six percent of the patients were highly active, with a UCLA score ≥ 7. Furthermore, the reported MCID, SCB, and PASS for mHHS were achieved by more than 80% of patients.

Return to Competitive Level of Play and Performance in Regular Golfers After Total Hip Arthroplasty: Analysis of 599 Patients at Minimum 2-Year Follow-Up

BACKGROUND

Total hip arthroplasty (THA) is performed in an increasingly younger and athletic population. Regular and competitive golfers are concerned with the likelihood of recovering their preoperative level of play. The purpose of this study was to assess the impact of primary THA on golfers' game, with a minimum follow-up of two years.

METHODS

Questionnaires were sent to the French Golf Federation's golfing members. Those who were older than 40 years and had undergone a unilateral primary THA provided information on the timing of return to play, pain during golfing, transportation mode, drive length, handicap and weekly playtime, before hip replacement, and postoperatively. In addition, data relating to the surgical procedure were collected.

RESULTS

Surveys were completed by 883 competitive golfers of which 599 were eligible for inclusion. The mean time to return to a complete 18-hole course was 4.73 months (SD 4.15, range: 0.7-36). Participants surveyed at a minimum 2 years after THA played at a higher level than before surgery with a handicap improvement of 1.8 (P < .01) and increased their mean weekly playtime from 8.8 to 9.3 hours (P = .24, NS). Eighty-eight percent reported an increased or no change in drive distance. Hip pain while playing golf decreased after surgery (6.8 to 2.5 on the visual analog scale, P < .001).

CONCLUSION

This study highlighted that hip arthroplasty allowed regular and competitive golfers to return to the course with better golfing comfort than before surgery and with an objective improvement in driving distance and level of play.

Short-term clinical and radiological results of two different design metaphyseal fitting femoral stems in total hip arthroplasty: a prospective, randomized trial

Background

There is great design variability on short femoral stems available on the market. This study aims to evaluate the short-term clinical and radiological results of two different design short femoral stems, both classified as shortened tapered stems.

Methods

From March 2016 to March 2018, a prospective, randomized, parallel-group design study was conducted to compare functional and radiological outcomes of 45 patients underwent THA using the Tri-Lock Bone Preservation Stem and 45 patients underwent THA with the Minima S stem at a minimum 2 years of follow-up. Patients were assessed clinically and radiographically prior to surgery as well as at 3, 6, 12, and 24 months postoperatively. Primary outcomes were the change in health-related quality of life assessed with Western Ontario and McMaster Universities Osteoarthritis Index and 36-Item Short Form Health Survey and also the incidence of all hip-related complications. Secondary aims included hip function evaluated with the Harris hip score, rates of patient satisfaction, and the outcomes of a detailed radiological analysis.

Results

There were no significant differences between the 2 study groups in terms of patient-reported outcomes measurements, satisfaction scores, and complication rates at any of the measurement times. In both groups, stable fixation and radiographic osseointegration were achieved. However, analysis of the calcar region showed that 57.8% and 28.9% of patients had grade 1 or 2 stress shielding, in Tri-Lock and Minima S implantation group, respectively (p=0.015). Regarding coronal alignment, stems were placed in slight varus, valgus, and neutral position in 51.1%, 13.3%, and 35.6% of patients, respectively, in Tri-Lock BPS group. The Minima S stem was implanted at slight varus and valgus in 60% and 40% of patients, respectively, and neither stem in the exact neutral position.

Conclusions

Both different design short femoral stems demonstrated excellent clinical performance at short-term follow up. Nevertheless, concerns were raised regarding the incidence of stress shielding phenomenon and mild discrepancies in coronal stem alignment during implantation. The clinical impact of these observations should be further evaluated through larger cohorts and longer follow-up.

Trial registration

ISRCTN registry, ISRCTN10096716. Registered on May 8, 2018—Retrospectively registered

Long-term Results of the Thrust Plate Prosthesis, 21-year Follow-up: A Case Report and Literature Review

Introduction:

The thrust plate prosthesis (TPP) is a type of cementless hip replacement. Aimed to preserve femoral diaphyseal bone, it was favored by some orthopedic surgeons in younger patients as they could potentially undergo multiple revision arthroplasties during their lifetime. Of particular note, the preserved diaphyseal bone allows for the implantation of a subsequent primary total hip arthroplasty (THA).

Case Report:

We reported on a 64-year-old male patient who underwent thrust plate prosthesis (TPP) implantation 21 years ago (1999) for the treatment of primary osteoarthritis (OA) of the right hip joint. At 21-year follow-up, he had not developed any post-operative complications, and he reported a SF12 score of 32 and Oxford hip score of 47/48.

Conclusion:

TPP proved to be successful clinically and radiologically, especially in the young patient. It loads directly to the cortex of the proximal femoral metaphysis as in a native hip joint. It is a bone preserving prosthesis which allows for good bone stock in the case of revision surgery that was a victim of commercial considerations.

Recommendations for return to sports after total hip arthroplasty are becoming less restrictive as implants improve

INTRODUCTION

Total hip arthroplasty (THA) surgeries are expected to exponentially increase in the upcoming years, likely because of the overall broader indication of THAs. With these developments, an increasing number of younger (< 50 years) and active patients will receive surgical interventions, and expectations for an active lifestyle will accordingly increase. In addition, surgeons now have a growing array of techniques and implant materials to choose from. Despite these developments, evidence to provide the best standard-of-care to patients with high expectations for return to sports (RTS) is scarce and urgently needed. What recommendations do arthroplasty surgeons currently make to patients with high return to sports expectations, what factors may influence their recommendations and what surgical techniques and implant specifications are considered favorable in the treatment of patients with a more active lifestyle? This study was conducted to analyze the current recommendations, patient assessment, and patient counseling after THA to identify trends and relevant factors for surgical decision-making in patients with high-RTS expectations.

MATERIAL AND METHODS

We designed a questionnaire comprising five general items and 19 specific items that included 46 sub-items for hip arthroplasty and conducted a survey among 300 German surgeons specialized in arthroplasty at the German Arthroplasty Society (AE) to assess expert opinions, recommendations, surgical decision-making, and patient counseling for patients with high expectations for RTS after THA.

RESULTS

The majority of surgeons (81.9%) were in favor of RTS after THA. Risks associated with sports after THA were considered minimal (1%), with periprosthetic fractures ranking highest, followed by hip dislocation and polyethylene wear. Some surgical decision-making was influenced by high-RTS expectations in regard to implant fixation, stem type, femoral head diameter, and bearing-surface tribology. We observed an increasingly liberal counseling of patients for high-impact sports.

CONCLUSION

With the improvement of implants and surgical techniques, surgeons are more willing to encourage patients to adopt a more active lifestyle. However, the true long-term limitations need further investigation in future studies.

LEVEL OF EVIDENCE

5 Expert opinions.

Comparative analysis of the biomechanical behavior of two different design metaphyseal-fitting short stems using digital image correlation

BACKGROUND

The progressive evolution in hip replacement research is directed to follow the principles of bone and soft tissue sparing surgery. Regarding hip implants, a renewed interest has been raised towards short uncemented femoral implants. A heterogeneous group of short stems have been designed with the aim to approximate initial, post-implantation bone strain to the preoperative levels in order to minimize the effects of stress shielding. This study aims to investigate the biomechanical properties of two distinctly designed femoral implants, the TRI-LOCK Bone Preservation Stem, a shortened conventional stem and the Minima S Femoral Stem, an even shorter and anatomically shaped stem, based on experiments and numerical simulations. Furthermore, finite element models of implant-bone constructs should be evaluated for their validity against mechanical tests wherever it is possible. In this work, the validation was performed via a direct comparison of the FE calculated strain fields with their experimental equivalents obtained using the digital image correlation technique.

RESULTS

Design differences between Trilock BPS and Minima S femoral stems conditioned different strain pattern distributions. A distally shifting load distribution pattern as a result of implant insertion and also an obvious decrease of strain in the medial proximal aspect of the femur was noted for both stems. Strain changes induced after the implantation of the Trilock BPS stem at the lateral surface were greater compared to the non-implanted femur response, as opposed to those exhibited by the Minima S stem. Linear correlation analyses revealed a reasonable agreement between the numerical and experimental data in the majority of cases.

CONCLUSION

The study findings support the use of DIC technique as a preclinical evaluation tool of the biomechanical behavior induced by different implants and also identify its potential for experimental FE model validation. Furthermore, a proximal stress-shielding effect was noted after the implantation of both short-stem designs. Design-specific variations in short stems were sufficient to produce dissimilar biomechanical behaviors, although their clinical implication must be investigated through comparative clinical studies.

Clinical and radiographic outcomes with the Nanos™ short-stem hip implant at 24 months: A prospective, single-center study

Aim

Short-stem total hip arthroplasty is designed to preserve proximal bone stock in case of eventual revision, potentially benefiting younger and more active patients. This prospective, single-center study assessed the safety and performance of the partially neck-sparing Nanos™ short-stem uncemented prosthesis at 24 months using clinical outcome scores and radiographic results.

Methods

Between April 2011 and February 2015, 52 subjects (mean age, 54.9 years) underwent total hip arthroplasty and were followed up at 3, 6, 12 and 24 months. The primary outcome was improvement in quality of life as measured by the Short-Form 36 Mental Component Score (SF-36 MCS). Secondary clinical outcomes included the Harris Hip Score, Hip Disability and Osteoarthritis Outcome Score, Postel Merle d'Aubigné-Score, Activity Level University of California, Los Angeles score, and Pain Visual Analogue Scale. Complications and radiographic images were also recorded at each follow-up.

Results

Mean SF-36 MCS score significantly improved from baseline to final follow up at 24 months (61.3 vs. 79.5, respectively; p < 0.001). All secondary clinical outcomes also showed significant improvement (p < 0.001) during this time period. Neutral stem positioning was achieved in 45 subjects (86.5%). Two subjects (3.8%) underwent revisions: one for a periprosthetic fracture unrelated to the study device and another due to a prosthetic joint infection. Intraoperatively, one fissure fracture of the acetabulum occurred.

Conclusion

Total hip arthroplasty with the Nanos short-stem led to significant clinical improvements and a high subjective satisfaction rate at 24 months. Further follow-up will determine whether these effects are sustained in the long term.

Prospective Short-Term and Return-to-Sports Results of a Novel Uncemented Short-Stem Hip Prosthesis with Metaphyseal Anchorage

Short-stem hip prostheses were developed to treat active patients requiring total hip arthroplasty (THA). This study provides short-term data about a short-stem total hip arthroplasty system. Functional and radiological outcomes as well as return to sports and activity level were assessed. A series of 55 patients was primarily included. Data were available for 47 patients at an average follow-up of 38 ± 4.6 months. The back-to-sports analysis showed a 98% return-to-sports rate (46/47 patients). The average time for return to sports was 13 weeks (± 8) postoperatively. Five patients (10.6%) were more active postoperatively. The Harris Hip Score (HHS) improved from 34.8 (±9.4) preoperatively to 94.7 (±8.4, p ≤ 0.001) and the University of California, Los Angeles (UCLA) score improved from 4.5 (±1.8) to 6.9 (±1.9) (p ≤ 0.001). The High Activity Arthroplasty Score (HAAS) was 12 (±3.6) at 3-year follow-up. Pre- and postoperative UCLA and postoperative HHS and HAAS scores had a positive influence on the return-to-sports rate (p ≤ 0.05). The collection of radiographic data during all postoperative follow-ups showed no signs of radiolucent lines or bone fissures. The complication rate was at 5%. Short-stem systems are equaling conventional prostheses and offer benefits regarding soft tissue and bone stock preservation. Fast recovery and return to sports can be achieved.

Comparison of short-stem with conventional-stem prostheses in total hip arthroplasty: an 8-year follow-up study

PURPOSE

Coxarthrosis is a common disease of the adult hip joint. Elderly patients have mainly been treated with total hip arthroplasty (THA); however, younger patients are increasingly affected. Short-stem prostheses were developed for this special patient group. There have been few studies on the clinical outcomes of this type of prosthesis. This study compared the mid-term results of a short-stem prosthesis and a standard-stem prosthesis 8 years after implantation.

METHODS

According to our clinical registry, patients who received a short-stem prosthesis before 2011 were identified. Patients in the standard-stem prosthesis group were matched based on the sex, age, height, weight, and degree of arthrosis. At the follow-up time, the modified Harris Hip Score (mHHS), University of California Los Angeles (UCLA) activity score and visual analog scale (VAS) pain score were collected and compared with the preoperative values.

RESULTS

Fifty-five patients could be matched and analyzed for both groups. No patients needed revision surgery. In both groups, there were significant improvements at the follow-up time. The pre- and postoperative mHHSs, UCLA scores, and VAS scores were 41.9 and 95 (p < 0.0001), 3.75 and 7.9 (p < 0.0001), and 7.6 and 0.9 (p < 0.0001), respectively, in the short-stem group and 44.8 and 96.25 (p < 0.0001), 3.6 and 7.7 (p < 0.0001), and 7.7 and 0.9 (p < 0.0001), respectively, in the control group, with no significant differences between the groups at the follow-up time.

CONCLUSION

The short-stem prosthesis provides mid-term results comparable to those of a standard-stem prosthesis. In both groups, excellent patient-reported outcomes were achieved after an average of 8 years.

LEVEL OF EVIDENCE

IV.

Return to Sport After Bilateral Single Stage Total Hip Arthroplasty Using the Direct Anterior Approach: A Case Control Study

BACKGROUND

Total hip arthroplasty (THA) is currently performed on active patients with increasing functional demands. Single stage bilateral THA is indicated in younger patients in good general health. Our objective is to evaluate the return to sport (RTS) in patients who underwent bilateral single stage THA compared to unilateral THA.

METHODS

This retrospective case control study was conducted between 2013 and 2017. All patients who underwent bilateral single stage THA were included. The control group had unilateral THA performed and was matched based on age, body mass index, gender, and surgery date (2 controls for each bilateral case). All surgeries were performed by a single senior surgeon using the direct anterior approach. The University of California Los Angeles activity score was collected at the last follow-up. A questionnaire regarding RTS, motivation, and satisfaction was assessed.

RESULTS

Thirty-two patients were included in the study, of whom 21 were men. The average age was 60.7 ± 9.6 years, body mass index was 26 ± 4 kg/m², and mean follow-up was 20.1 ± 11.6 months. Twenty-eight patients overall (87%) returned to sport after the procedure. Twenty-five of these (89%) returned to the same sport, and 17 (68%) participated at the same intensity. The average time to RTS was 4 ± 2.8 months. These results were at least as good as those after unilateral THA. The level of motivation of the patient was the only predictive factor for RTS (P < .001).

CONCLUSION

Bilateral single stage THA via a direct anterior approach allows for RTS and to a similar level in the majority of patients in whom this procedure is indicated.

LEVEL OF EVIDENCE

Comparative retrospective study, Level III.

Return to Sport After Short-Stem Total Hip Arthroplasty

OBJECTIVES

Information about sport activity after short-stem total hip arthroplasty (THA) is scarce in the literature. We therefore aimed to evaluate the rate of return to sport after short-stem THA.

METHODS

We evaluated the sport pattern, rate of return to sport, activity level, extent of sport activity, and subjective rating and sense of well-being in 137 patients (137 hips) after short-stem THA. The minimum follow-up time was 18 months. All results were analyzed according to gender (male and female) and age (≤60, >60-≤70, and >70 years).

RESULTS

Ninety-two percent of all patients practiced sport before surgery, and 91% of the patients returned to sport. Most patients returned to sport within the first 6 months after surgery. There was a decline in the number of sport disciplines from preoperatively to postoperatively, which was from 2.9 to 2.6 (P = 0.025). High-impact activities decreased postoperatively, but most low-impact activities did not change significantly. Eighty percent of all patients were involved in recreational sports.

CONCLUSION

In this study, we observed an excellent rate of return to sport after short-stem THA. Most patients returned to the same level of sport activity that they had before the onset of restricting symptoms, with the majority of patients having a great sense of well-being during and after sports, and almost no pain in the affected hip.

Return to Sports and Recreational Activity After Single-Stage Bilateral Short-Stem Total Hip Arthroplasty: 5-Year Results of a Prospective Observational Study

Background:

Single-stage bilateral total hip arthroplasty (THA) is an alternative to staged unilateral THA in patients suffering from bilateral hip arthritis; however, there is still broad concern regarding the safety and reliability of this procedure. Short-stem THA has emerged in recent years. To date, no data are available on sports and recreational activity levels after single-stage bilateral short-stem THA in the general patient population.

Hypothesis:

Patients who have undergone single-stage bilateral short-stem THA return to a satisfying level of sports and recreational activity at midterm follow-up.

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 54 consecutive patients (108 hips) were prospectively included. Midterm follow-up was performed in 51 patients (94.4%). The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score and the Harris Hip Score (HHS) were assessed clinically after a mean of 5.2 years. After a mean of 4.9 years, activity levels were assessed using the University of California, Los Angeles (UCLA) activity scale via a questionnaire. Additionally, a detailed evaluation of sports behavior was conducted using an additional questionnaire. Pain and satisfaction with sporting ability were assessed using a visual analog scale (VAS). Complications and revisions were documented.

Results:

Patients had a mean WOMAC score of 98.0 (range, 60.0-100.0) and HHS score of 97.8 (range, 65.0-100.0) at final follow-up. The mean UCLA activity score was 4.7 (range, 2.0-10.0). An increasing number of patients were active in sports at follow-up compared with before surgery (76.5% vs 60.8%, respectively); 2 patients (3.9%) stopped participating in sports on a regular basis, and 10 (19.6%) commenced with sports after surgery. The most popular activities before surgery were cycling (31.4%), hiking (29.4%), swimming (21.6%), and fitness/weight training (15.7%). At follow-up, most patients were engaged in cycling (35.3%) and fitness/weight training (33.3%), followed by swimming (25.5%) and hiking (19.6%). The duration (hours per week) and frequency (times per week) of sporting activities remained stable. The mean VAS pain level during sports was 1.3 (range, 0.0-7.0). No revision surgery had to be performed.

Conclusion:

After single-stage bilateral short-stem THA, the study patients returned to satisfying levels of activity at midterm follow-up. Postoperatively, few patients were engaged in high-impact sports; however, more patients commenced with lower impact activities. Satisfaction with sporting abilities was high, and the complication rate in total was low.

Patient-reported outcomes in hip resurfacing versus conventional total hip arthroplasty: a register-based matched cohort study of 726 patients

Background and purpose - The theoretical mechanical advantages of metal-on-metal hip resurfacing (MoM-HR) compared with conventional total hip arthroplasty (THA) have been questioned. Studies including measures of patient-reported function, physical activity, or health-related quality of life have been sparse. We compared patient-reported outcomes in MoM-HR patients with a matched group of patients with conventional THA at 7 years post-surgery. Patients and methods - Patients and patient data were retrieved from the Swedish Hip Arthroplasty Register. The case group, consisting of 363 patients with MoM-HR, was matched 1:1 with a control group, consisting of patients with a conventional THA. Patients were sent a postal patient-reported outcome measures (PROM) questionnaire including the Hip Disability and Osteoarthritis Outcome Score (HOOS), EQ-5D, and VAS pain. We used multivariable linear regression analyses to investigate the influence of prosthesis type. Results - 569 patients (78%) returned the questionnaire with complete responses (299 MoM-HRs and 270 conventional THAs). MoM-HR was associated with better scores in HOOS function of daily living (4 percentage units) and HOOS function in sport and recreation (8 percentage units) subscales. Type of prosthesis did not influence HOOS quality of life, HOOS pain, HOOS symptoms, EQ-5D index, hip pain, or satisfaction as measured with visual analog scales. Interpretation - At mean 7 years post-surgery, patients with hip resurfacing had somewhat better self-reported hip function than patients with conventional THA. The largest difference between groups was seen in the presumed most demanding subscale, i.e., function in sport and recreation.

Comparison of two metaphyseal-fitting (short) femoral stems in primary total hip arthroplasty: study protocol for a prospective randomized clinical trial with additional biomechanical testing and finite element analysis

BACKGROUND

Total hip replacement has recently followed a progressive evolution towards principles of bone- and soft-tissue-sparing surgery. Regarding femoral implants, different stem designs have been developed as an alternative to conventional stems, and there is a renewed interest towards short versions of uncemented femoral implants. Based on both experimental testing and finite element modeling, the proposed study has been designed to compare the biomechanical properties and clinical performance of the newly introduced short-stem Minima S, for which clinical data are lacking with an older generation stem, the Trilock Bone Preservation Stem with an established performance record in short to midterm follow-up.

METHODS/DESIGN

In the experimental study, the transmission of forces as measured by cortical surface-strain distribution in the proximal femur will be evaluated using digital image correlation (DIC), first on the non-implanted femur and then on the implanted stems. Finite element parametric models of the bone, the stem and their interface will be also developed. Finite element predictions of surface strains in implanted composite femurs, after being validated against biomechanical testing measurements, will be used to assist the comparison of the stems by deriving important data on the developed stress and strain fields, which cannot be measured through biomechanical testing. Finally, a prospective randomized comparative clinical study between these two stems will be also conducted to determine (1) their clinical performance up to 2 years' follow-up using clinical scores and gait analysis (2) stem fixation and remodeling using a detailed radiographic analysis and (3) incidence and types of complications.

DISCUSSION

Our study would be the first that compares not only the clinical and radiological outcome but also the biomechanical properties of two differently designed femoral implants that are theoretically classified in the same main category of cervico-metaphyseal-diaphyseal short stems. We can hypothesize that even these subtle variations in geometric design between these two stems may create different loading characteristics and thus dissimilar biomechanical behaviors, which in turn could have an influence to their clinical performance.

TRIAL REGISTRATION

International Standard Randomized Controlled Trial Number, ID: ISRCTN10096716 . Retrospectively registered on May 8 2018.

Perceived skills for sports performance after primary hip arthroplasty: a cross-sectional study

PURPOSE

Recommendations arising from existing literature regarding restrictions and benefits of sporting activities after joint replacement surgery vary widely. As hip arthroplasty patients are becoming increasingly active, their expectations about post-operative function are constantly evolving. The aim of this study is to identify the perception of patients regarding their performance in sports activities after hip arthroplasty.

METHODS

This cross-sectional study included all patients undergoing primary hip arthroplasty, for any diagnosis, between January 2009 and January 2016. By applying a telephone survey, practice of sports before surgery, resumption after surgery, level of performance, and causes of non-resumption of sports activities were assessed.

RESULTS

Data of 531 patients were obtained. Of these, 13% were engaged in sports before surgery. The most frequently practiced sports were golf (27.5%) and tennis (22%). Of the 72 patients that practiced sports, only 44.4% (30 patients) returned to this activity after surgery. Nonetheless, 71% of these patients reported to have an equal or better athletic performance than before surgery. The main causes reported by patients not to return to sports were the fear of injury and recommendation of the surgeon.

CONCLUSIONS

A significant number of patients return to sports after hip arthroplasty and most of them perceive a good athletic performance after surgery. These findings should enrich the pre-operative assessment of patient's expectations, particularly for those who wish to resume physical activity.

Return to sport after lower limb arthroplasty - why not for all?

BACKGROUND

Total hip and knee replacements are being performed in increasing numbers in progressively younger patients with higher activity demands. Many such patients have expectations of returning to athletic activity post-operatively yet are not always able to do so and the reasons behind this have not been extensively examined. We hypothesise that any reasons for a failure to return to athletic activity post-operatively are multi-factorial.

AIM

To quantify the return to athletic activity following lower limb joint arthroplasty and understand qualitative reasons for altered activity participation.

METHODS

A single centre, single surgeon retrospective questionnaire for hip and knee arthroplasty patients under age 60 years, minimum two years post-surgery with exclusion criteria of multiple degenerative joint involvement and multiple medical co-morbidities. Outcomes were validated joint-specific (Oxford hip and knee) and lifestyle questionnaires [short form 12 (SF-12) and University of California, Los Angeles (UCLA)] and an activity questionnaire assessing ability participation in athletic activity post-operatively. Statistical analysis was performed on the validated outcome data, including comparison between hip and knee replacements. Frequency tables were produced to quantify the different athletic activities participated in by patients.

RESULTS

Responses were received from 64 patients (80% response rate). There was a statistically significant improvement in Oxford hip and knee scores following surgery. SF-12 scores also improved for all patients, but no statistically significant difference was seen between joints (P = 0.88). Mean UCLA scores pre-operatively were 7.67 and at two years post-operatively were 7.69, with no statistically significant change (P = 0.91). All patients reported high satisfaction and improved ability to perform athletic activity at a higher frequency compared to pre-operatively. The most common reasons for changing activity participation were not wanting to stress their joint replacement or instructions by other doctors or the lead surgeon. There was no difference in the responses to the questionnaire based on type of joint replacement (P = 0.995).

CONCLUSION

Patients receiving a joint replacement are able to participate in athletic activity to high levels and are satisfied with their outcomes. Reasons for non-participation are multi-factorial.

The Effect of Total Hip Arthroplasty on Sports and Work Participation: A Systematic Review and Meta-Analysis

Background

Total hip arthroplasty (THA) is a successful procedure to treat end-stage hip osteoarthritis. The procedure is increasingly performed in adults of working age, who often wish to return to sports (RTS) and return to work (RTW). However, a systematic overview of the evidence on RTS and RTW after THA is lacking.

Objectives

Our aim was to systematically review (1) the extent to which patients RTS and RTW after THA, including (2) the time to RTS and RTW.

Methods

We searched MEDLINE and Embase from inception until October 2017. Two authors screened and extracted the data, including study information, patient demographics, rehabilitation protocols and pre- and postoperative sports and work participation. Methodological quality was assessed using the Newcastle–Ottawa scale. Data on pre- and postoperative sports and work participation were pooled using descriptive statistics.

Results

A total of 37 studies were included, of which seven were prospective studies and 30 were retrospective studies. Methodological quality was high in 11 studies, moderate in 16 studies, and low in ten studies. RTS was reported in 14 studies. Mean RTS was 104% to the pre-surgery level and 82% to the pre-symptomatic sports level. Time to RTS varied from 16 to 28 weeks. RTW was reported in 23 studies; the mean was 69%. Time to RTW varied from 1 to 17 weeks.

Conclusion

A great majority of patients RTS and RTW after THA within a timeframe of 28 and 17 weeks, respectively. For the increasingly younger THA population, this is valuable information that can be used in the preoperative shared decision-making process.

Electronic supplementary material

The online version of this article (10.1007/s40279-018-0924-2) contains supplementary material, which is available to authorized users.

Uncemented short stems in primary total hip arthroplasty: The state of the art

Over the last two decades, several conservative femoral prostheses have been designed. The goals of conservative stems include: the spearing of the trochanteric bone stock; a more physiological loading in the proximal femur reducing the risk of stress shielding; and to avoid a long stem into the diaphysis preventing impingement with the femoral cortex and thigh pain.

All stems designed to be less invasive than conventional uncemented stems are commonly named ‘short stems’. However, this term is misleading because it refers to a heterogeneous group of stems deeply different in terms of design, biomechanics and bearing. In the short-term follow-up, all conservative stems provided excellent survivorship. However, variable rates of complications were reported, including stem malalignment, incorrect stem sizing and intra-operative fracture.

Radiostereometric analysis (RSA) studies demonstrated that some conservative stems were affected by an early slight migration and rotation within the first months after surgery, followed by a secondary stable fixation. Dual-energy x-ray absorptiometry (DEXA) studies demonstrated an implant-specific pattern of bone remodelling.

Although the vast majority of stems demonstrated a good osseointegration, some prostheses transferred loads particularly to the lateral and distal-medial regions, favouring proximal stress shielding and bone atrophy in the great trochanter and calcar regions.

Cite this article: EFORT Open Rev 2018;3:149-159. DOI: 10.1302/2058-5241.3.170052

High incidence of early subtrochanteric lateral cortical atrophy after hip arthroplasty using bone-conserving short stem

PURPOSE

Load transfer to the bone is believed to be more physiological around the short stem in total hip arthroplasty (THA). However, we found unusual bony remodeling around the shortened tapered stem. This study was performed to investigate the extent and frequency of this phenomenon and to find the possible risk factors of it.

METHODS

Among 121 consecutive THA using the same short stem, 80 THAs were enrolled. Radiographic measurements were made using anteroposterior (AP) radiographs taken immediately and at two years after surgery. The thickness of the lateral cortex at the level of the distal end of the coated surface and at 10, 20, 30, and 40 mm proximal to it were measured.

RESULTS

Significant atrophy was noted in all regions (P < 0.001 each). In 46 cases, this presented as an intra-cortical osteolytic line (IOL). Sixty-one cases showed either an IOL or atrophy >10%. The risk of a mean reduction >20% was related to an increased operating time (odds ratio [OR] = 0.981; 0.966 < 95% confidence interval [CI] < 0.996) and lower body mass index (BMI) (OR = 1.216; 1.043 < 95% CI < 1.417). Periprosthetic fracture through the lateral cortex occurred in one case.

CONCLUSION

Even with THA using a shortened stem, high incidence of proximal stress shielding was noted in the form of lateral cortical atrophy, especially for the patient with low BMI.

Early performance-based and patient-reported outcomes of a contemporary taper fit bone-conserving short stem femoral component in total hip arthroplasty

Aims

The aim of this study was to compare early functional and health related quality of life outcomes (HRQoL) in patients who have undergone total hip arthroplasty (THA) using a bone conserving short stem femoral component and those in whom a conventional length uncemented component was used. Outcome was assessed using a validated performance based outcome instrument as well as patient reported outcome measures (PROMs).

Patients and Methods

We prospectively analysed 33 patients whose THA involved a contemporary proximally porous coated tapered short stem femoral component and 53 patients with a standard conventional femoral component, at a minimum follow-up of two years. The mean follow-up was 31.4 months (24 to 39). Patients with poor proximal femoral bone quality were excluded. The mean age of the patients was 66.6 years (59 to 77) and the mean body mass index was 30.2 kg/m2 (24.1 to 41.0). Outcome was assessed using the Oxford Hip Score (OHS) and the University College Hospital (UCH) hip score which is a validated performance based instrument. HRQoL was assessed using the EuroQol 5D (EQ-5D).

Results

There were no major peri-operative complications. There was no difference in the mean post-operative OHS, EQ-5D or function subscale of the UCH hip scores between the two groups. The mean pre-operative OHS and EQ-5D scores improved significantly (all p <  0.001). The mean functional component of the UCH hip score at final follow-up was 42.5 and 40.6 in the short stem and conventional stem groups, respectively. There was no statistically significant difference between the groups (p = 0.42). A total of seven patients (21.2%) in the short stem group and nine (16.98%) in the conventional group achieved a ceiling effect using the OHS; none did using the function subscale of the UCH hip score.

Conclusion

The proximally porous coated tapered short stem femoral component achieves comparable short-term functional outcomes when compared with a conventional longer stem uncemented femoral component when THA is undertaken in patients with good bone quality. Cite this article: Bone Joint J 2017;99-B(4 Supple B):49–55.

Comparative Analysis of the Biomechanical Behaviour of Two Cementless Short Stems for Hip Replacement: Linea Anatomic and Minihip

A comparative study between two stems (Linea Anatomic and Minihip) has been performed in order to analyse the differences in their biomechanical behaviour, concerning stem micromotions and load transmission between stem and bone. From the corresponding finite element models, a parametric study was carried out to quantify ranges of micromotions taking into account: friction coefficient in the stem-bone interface, press-fit and two types of gait cycle. Micromotions were evaluated for each stem at six different levels along repeated gait cycles. An initial and marked stem subsidence at the beginning of the simulation was observed, followed by an asymptotic decrease due to friction forces. Once migration occurs, a repeated reversible cyclic micromotion is developed and stabilized as gait cycle times are simulated. The general motion pattern exhibited higher amplitude of micromotion for Minihip compared to Linea stem. The load transmission mechanism was analyzed, identifying the main internal forces. The results show higher local forces for Minihip stem up to 80% greater than for Linea stem. The differences of design between Minihip and Linea conditioned different distributions of load, influencing the posterior stress-shielding. Consequently, short stems require high bone stock and quality should, being indicated for young patients with high bone quality.

Dynamic Hip Kinematics During the Golf Swing After Total Hip Arthroplasty

BACKGROUND

Although most surgeons allow their patients to play golf after total hip arthroplasty (THA), the effect on the implant during the golf swing is still unclear.

PURPOSE

To evaluate hip kinematics during the golf swing after THA.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Eleven hips in 9 patients who underwent primary THA were analyzed. All patients were right-handed recreational golfers, and these 11 hips included 6 right hips and 5 left hips. Periodic radiographic images of the golf swing were taken using a flat-panel x-ray detector. Movements of the hip joint and components were assessed using 3-dimensional-to-2-dimensional model-to-image registration techniques. Liner-to-neck contact and translation of the femoral head with respect to the acetabular cup (cup-head translation) were examined. Hip kinematics, orientation of components, and maximum cup-head translation were compared between patients with and without liner-to-neck contact.

RESULTS

On average, the golf swing produced approximately 50° of axial rotation in both lead and trail hips. Liner-to-neck contact was observed in 4 hips with elevated rim liners (2 lead hips and 2 trail hips) at maximum external rotation. Neither bone-to-bone nor bone-to-implant contact was observed at any phases of the golf swing in any of the hips. Four hips with liner-to-neck contact had significantly larger maximum external rotation (37.9° ± 7.0° vs 20.6° ± 9.9°, respectively; P = .01) and more cup anteversion (26.5° ± 6.1° vs 10.8° ± 8.9°, respectively; P = .01) than hips without liner-to-neck contact. No significant differences between hips with and without contact were found for cup inclination (42.0° ± 2.5° vs 38.1° ± 5.5°, respectively; P = .22), combined anteversion (45.3° ± 8.9° vs 51.4° ± 7.9°, respectively; P = .26), or maximum cup-head translation (1.3 ± 0.3 mm vs 1.5 ± 0.4 mm, respectively; P = .61).

CONCLUSION

In this analysis, the golf swing did not produce excessive hip rotation or cup-head translation in any hips. However, liner-to-neck contact during the golf swing was observed in 36% of the hips, with unknown effects on the long-term results.

CLINICAL RELEVANCE

Golf is an admissible sport after THA because dynamic hip stability was observed. However, the implant position, especially cup anteversion and the use of elevated rim liners, promoted liner-to-neck contact.

Sports Activity after Low-contact-stress Total Knee Arthroplasty - A long term follow-up study

The purpose of this study was to provide comprehensive long-term data about sports activity levels in patients following total knee arthroplasty (TKA) and to determine the impact of pre-operative function, pain and specific performed sports on the results. 236 patients who have undergone TKA for severe osteoarthritis of the knee were asked to provide specific information regarding exercised types of sports before surgery and after at least 10 years following TKA. Pre- and postoperative function and pain were evaluated by the use of Tegner-, WOMAC- and VAS Score. After a mean of 14.9 years, a significant improvement regarding pain and function was observed. Pre-operative Tegner- and WOMAC scores revealed significant positive correlations with the post-operative Tegner-Score. Accordingly, a high percentage of patients (70.9%) stayed actively involved in sports. Nevertheless, the number of performing patients has decreased according to the sports impact. 71.3% continued practising low-impact-, 43.7% intermediate-impact sports whereas only 16.4% kept performing high impact sports. We conclude that TKA is highly effective in long-time pain reduction as well as improvement of function. Additionally, we found considerable sports activities preserved in the investigated series. However, sports activities in particular, seem to decrease according to the impact of sports.

A short-stem hip implant with metaphyseal anchorage in patients with developmental dysplasia of the hip

BACKGROUND

Short-stem implants are routinely used for total hip arthroplasty in younger patients that are more likely to have secondary osteoarthritis than older patients.

OBJECTIVE

To investigate the applicability of short-stem hip implants for secondary osteoarthritis due to developmental dysplasia of the hip.

METHODS

This study analyzed the clinical and radiological results of patients with developmental dysplasia of the hip (DDH, 58 hips) and compared them to those of patients with primary osteoarthritis (POA, 59 hips) treated with the metaphyseal total hip arthroplasty (Metha®) short stem with metaphyseal fixation.

RESULTS

The mean clinical and radiological follow-up periods were 2.9 ± 1.1 years and 3.8 ± 1.9 years, respectively. The mean Harris Hip Score (HHS) significantly increased in both groups over this period (p< 0.0001). The caput-collum-diaphysis (CCD) angle was significantly lower in the POA group prior to surgery and significantly increased in the POA and and decreased in DDH groups, respectively. The preoperative femoral offset was lower in the DDH group and increased significantly after surgery.

CONCLUSIONS

The Metha® short stem in patients with DDH allows good reconstruction of joint biomechanics with a good clinical outcome.

Influence of patient-related characteristics on early migration in calcar-guided short-stem total hip arthroplasty: a 2-year migration analysis using EBRA-FCA

Background

Short stems have gained popularity in recent years. Because of encouraging clinical results, indications have been expended from young to elderly and obese patients. However, long-term results are lacking. The purpose of this study was to evaluate the influence of gender, age, body weight, body mass index (BMI), and offset version on short-stem migration in correlation to the clinical outcome.

Methods

The implant migration of 202 metaphyseal-anchoring, calcar-guided short stems in 151 patients was assessed by “Einzel-Bild-Roentgen-Analyse” femoral component analysis (EBRA-FCA, femoral component analysis) in a 2-year follow-up. Full weight bearing was allowed directly after surgery. Patients were divided into groups regarding gender, age, body weight, BMI, and offset version. The Harris hip score (HHS) and satisfaction on visual analogue scale (VAS) were analyzed.

Results

After 2 years, mean axial subsidence of all 202 implants was 1.43 mm (standard deviation, SD 1.45 mm). A continuous reduction of initially pronounced subsidence over time could be observed. None of the stems had to be revised. Statistically significant increased rates of subsidence were seen in male (1.68 mm; SD 1.56 mm; p = 0.005) and heavy patients (1.54 mm; SD 1.48 mm; p = 0.022). No differences in implant migration were found regarding age, BMI, and different offset versions. HHS improved markedly from 45.8 (SD 15.9) to 98.1 (SD 4.7) while satisfaction on VAS improved from 1.8 (SD 2.2) to 9.7 (SD 0.9) after 2 years.

Conclusions

The results suggest a migration pattern with initially pronounced subsidence followed by subsequent stabilization. Male and obese patients show a slightly increased initial subsidence without any signs of sustained micromovement. No correlation was found concerning clinical results and pronounced initial subsidence above the threshold of 1.5 mm. No aseptic loosening or other signs of implant failure were seen within the observation period of 2 years.

Trial registration

German Clinical Trials Register, DRKS00009834.

Bone remodelling after femoral short stem implantation in total hip arthroplasty: 1-year results from a randomized DEXA study

INTRODUCTION

Short stem prostheses have been developed to preserve proximal femoral bone stock. This prospective, randomized study compared periprosthetic bone remodelling following short and straight stem implantation 1 year after surgery.

MATERIALS AND METHODS

One hundred and forty-four consecutive patients undergoing total hip arthroplasty were randomized to either a Fitmore short or a cementless straight stem (both Zimmer, Winterthur, Switzerland). Periprosthetic bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry performed the day before surgery and at 7 days, 3 months and 1 year postoperatively. Furthermore, the HHS and the WOMAC were obtained.

RESULTS

One hundred and thirty-eight patients completed 1-year follow-up. Periprosthetic BMD changes at 1 year were most pronounced in the proximal medial region of interest (ROI) 7 with -17.2% after short stem and -16.7% after straight implantation (p = 0.67). However, there was significantly less BMD reduction in ROI 6 following short (-4.7%) versus straight stem (-10.8%) implantation (p = 0.01). There were no significant differences between the two groups in terms of the HHS and the WOMAC either before or after surgery.

CONCLUSION

One year after surgery, both stems showed an implant-specific periprosthetic bone remodelling. Nevertheless, proximal load transfer was more pronounced after short stem implantation than with a straight stem.

Total hip arthroplasty using a short-stem prosthesis: restoration of hip anatomy

PURPOSE

To evaluate hip parameters such as vertical centre of rotation (VCR), horizontal centre of rotation (HCR), femoral offset, and leg length after total hip arthroplasty (THA) using the Nanos short-stem prosthesis.

METHODS

Medical records of 73 men and 74 women aged 25 to 92 (mean, 63) years who underwent THA using the Nanos short-stem prosthesis by a single surgeon were reviewed. Prior to the surgery, the optimal cup and stem size, head length, and level of the neck osteotomy were determined using radiographs. Intra-operatively, the leg length and femoral offset were checked, and the level of neck resection and head length were adjusted. VCR, HCR, femoral offset, and leg length of the operated and contralateral sides were compared. Functional outcomes were assessed using the Harris Hip Score (HHS).

RESULTS

Compared with the normal contralateral hips, the operated hips had a mean increase of 0.4 mm in VCR (p=0.032), a mean decrease of 1.4 mm in HCR (p=0.027), a mean increase of 0.6 mm in femoral offset (p=0.043), and a mean increase of 0.36 mm in leg length (p=0.035). For these respective parameters, the difference between the normal contralateral side and the operated side was within 5 mm in 89%, 80%, 71%, and 96% of patients. The HHS improved from a mean of 53 to 91 at one year (p<0.001).

CONCLUSION

THA using the Nanos short-stem prosthesis enabled restoration of hip anatomy (VCR, HCR, femoral offset, and leg length).

Sports activity after treatment of residual hip dysplasia with triple pelvic osteotomy using the Tönnis and Kalchschmidt technique

BACKGROUND

Pelvic osteotomies are performed to prevent the progression of osteoarthritis and its associated pain due to adult hip dysplasia, particularly for young patients with no or low-grade osteoarthritis. No data are available concerning levels of sporting activity before and after triple pelvic osteotomy (TPO). Therefore, the aim of this study was to provide comprehensive data on levels of sporting activity and the subjective outcome of patients after this complex operation.

HYPOTHESIS

Patients can return to a higher level of sports activity after TPO compared with their preoperative level.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between 2003 and 2011, a total of 116 triple pelvic osteotomies were performed at a single institution; the Tönnis and Kalchschmidt technique was used on 91 patients. After exclusion criteria for this study were applied, 77 patients remained (59 females and 18 males); the mean ± SD age at operation was 26 ± 3.9 years. To study outcomes, patients were asked to complete both the Harris hip score (HHS) and the Hip disability and Osteoarthritis Outcome Score (HOOS) preoperatively and at postoperative follow-up. Their level of activity was determined according to the University of California, Los Angeles (UCLA) activity score. Patients rated their hip movement and overall satisfaction preoperatively and at postoperative follow-up using a visual analog scale for sporting activity, physical fitness level, and level of pain experienced while performing their sport.

RESULTS

The mean ± SD follow-up time was 6.2 ± 1.4 years. The mean HHS changed significantly from 63.3 ± 15.6 preoperatively to 90.1 ± 10.8 at follow-up (P < .001), and the mean HOOS changed significantly from 52.9 ± 20.1 to 82 ± 17.1 at follow-up (P < .001). The mean UCLA activity score changed significantly from 4.8 ± 2.1 to 7.7 ± 1.4 at follow-up (P < .001).

CONCLUSION

Patients achieved a higher level of sports activity postoperatively. The postoperative level of participation in sports was superior, with a shift from low- to high-impact activities.

Short bone-conserving stems in cementless hip arthroplasty

➤ Short bone-conserving femoral stems in total hip arthroplasty were designed to preserve proximal bone stock.➤ Given the distinct fixation principles and location of loading among these bone-conserving stems, a classification system is essential to compare clinical outcomes.➤ Due to the low quality of currently available evidence, only a weak recommendation can be provided for clinical usage of certain stem designs, while some other designs cannot be recommended at this time.➤ A high prevalence of stem malalignment, incorrect sizing, subsidence, and intraoperative fractures has been reported in a subset of these short stem designs.➤ Stronger evidence, including prospective multicenter randomized trials comparing standard stems with these newer designs, is necessary before widespread use can be recommended.

Activity Tolerance After Periacetabular Osteotomy

BACKGROUND

Periacetabular osteotomy is a well-described surgical intervention for symptomatic acetabular deformities in skeletally mature patients. Data regarding return to athletic activity or sport after this procedure are still limited.

PURPOSE

To evaluate the ability of patients to return to preoperative levels of activity after periacetabular osteotomy.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This is a retrospective review of active patients treated with periacetabular osteotomy for acetabular deformity correction. Patients were identified as those with preoperative University of California-Los Angeles activity levels ≥7. Patient demographics, operative data, radiographic measures, and clinical outcomes were documented prospectively. The University of California-Los Angeles activity score, Harris Hip Score, Hip Dysfunction and Osteoarthritis Outcome Score, and Western Ontario and McMaster Universities Osteoarthritis Index were used to measure clinical outcomes, and details regarding activity and satisfaction were analyzed.

RESULTS

This study included 36 patients (39 hips; 15 males and 21 females) whose average age was 25 years (range, 15-45 years) and whose average body mass index was 24 ± 3.5 kg/m(2). Mean follow-up was 33 months (range, 18-59 months). Preoperatively, the average lateral center edge angle, anterior center edge angle, and acetabular index were 10°, 14°, and 21°, respectively; 92% of patients had a Tönnis osteoarthritis grade of 0 or 1. One patient failed hip preservation surgery and went on to total hip arthroplasty 27 months after periacetabular osteotomy. Of the remaining patients, 71% reported an increase or no change in activity level postoperatively. The University of California-Los Angeles score was also unchanged (9.2 vs 8.8, P = .157), and the Harris Hip Score (63 vs 87, P < .001), Hip Dysfunction and Osteoarthritis Outcome Score-Quality of Life (38 vs 71, P < .001), and Western Ontario and McMaster Universities Osteoarthritis Index (71 vs 92, P < .001) results improved from preoperative levels. There was a 97% rate of satisfaction with the surgery. Four patients (11%) reported hip pain as the primary factor limiting postoperative activity.

CONCLUSION

The majority (71%) of active patients with hip dysplasia return to presurgical or higher activity levels after open hip preservation surgery with the periacetabular osteotomy.

The role of activity level in orthopaedics: an important prognostic and outcome variable

A patient's activity level is increasingly recognized as an important factor that can influence orthopaedic outcomes. Validated, reliable activity measurement tools now exist for the shoulder, hip, knee, and ankle. These tools can be directly applied as outcome measures that determine whether interventions restored function. It is now evident that activity level is a powerful prognostic factor for outcomes in orthopaedic procedures such as anterior cruciate ligament reconstruction, articular cartilage repair, and total joint arthroplasty. Yet despite the recent increase in studies that have made use of quantitative, joint-specific activity scales, much room remains for further understanding of the exact role of activity level in the progression, treatment, and patient perception of musculoskeletal disorders, particularly in the shoulder and ankle, as well as in pediatric patients.

Athletic activity after lower limb arthroplasty

In this systematic review, our aim was to explore whether or not patients are able to return to athletic activity following lower limb joint replacement. We also investigated any evidence as to whether participation in athletic activity post-joint replacement increases complications and reduces implant survival.

A PubMed, Embase and Sports Discus search was performed using the MeSH terms ‘Sport’, ‘Athletic’, ‘Athlete’, ‘Physical’, ‘Activity’, ‘Arthroplasty’, ‘Total Hip Replacement’, ‘Hip Resurfacing’, ‘Total Knee Replacement’, ‘Unicompartmental Knee Replacement’ and ‘Unicondylar Knee Replacement’. From this search, duplications were excluded, the remaining abstracts were reviewed and any unrelated to the search terms were excluded. The remaining abstracts had their full papers reviewed.

Following joint replacement, participation in sporting activity is common principally determined by pre-operative patient activity levels, BMI and patient age. The type of joint replaced is of less significance. Total time spent performing activity does not change but tends to be at a lower intensity. There is little evidence in the literature of an association between high activity levels and early implant failure.

Cite this article: Bone Joint J 2014;96-B:923–7.

Changes in strain patterns after implantation of a short stem with metaphyseal anchorage compared to a standard stem: an experimental study in synthetic bone

Short stem hip arthroplasties with predominantly metaphyseal fixation, such as the METHA® stem (Aesculap, Tuttlingen, Germany), are recommended because they are presumed to allow a more physiologic load transfer and thus a reduction of stress-shielding. However, the hypothesized metaphyseal anchorage associated with the aforementioned benefits still needs to be verified. Therefore, the METHA short stem and the Bicontact® standard stem (Aesculap, Tuttlingen, Germany) were tested biomechanically in synthetic femora while strain gauges monitored their corresponding strain patterns. For the METHA stem, the strains in all tested locations including the region of the calcar (87% of the non-implanted femur) were similar to conditions of synthetic bone without implanted stem. The Bicontact stem showed approximately the level of strain of the non-implanted femur on the lateral and medial aspect in the proximal diaphysis of the femur. On the anterior and posterior aspect of the proximal metaphysis the strains reached averages of 78% and 87% of the non-implanted femur, respectively. This study revealed primary metaphyseal anchorage of the METHA short stem, as opposed to a metaphyseal-diaphyseal anchorage of the Bicontact stem.

Ten year results of the collum femoris preserving total hip replacement: a prospective cohort study of seventy five patients

PURPOSE

The collum femoris preserving (CFP) uncemented prosthesis has a bone-preserving, high subcapital neck resection and a short anatomical stem. The ideal arthroplasty option in the younger, active patient is a subject of some debate. We evaluated midterm outcomes of the CFP in this patient population.

METHODS

A prospective, consecutive cohort of 75 CFP total hip replacement (THR) patients with a mean age of 52 years was followed for a mean of 9.3 years. Patients were assessed using the Harris Hip Score (HHS). Pain was assessed using a visual analogue scale (VAS) and activity levels using the University of California, Los Angeles (UCLA) score. Radiographs were evaluated for evidence of loosening. Survivorship was calculated with an endpoint of revision for aseptic loosening or radiographic evidence of loosening.

RESULTS

Mean HHS improved from a mean of 50 pre-operatively to 91 (p < 0.001) postoperatively. Mean pain score was 1, mean patient satisfaction was 9 and mean UCLA score was 6. Two acetabular components were revised for aseptic loosening; no stem required revision. Radiographically, no cases had evidence of loosening. Survivorship was 96.8 % for the acetabular component and 100 % for the stem at ten years. Three patients died from unrelated causes, and five were lost to follow-up.

CONCLUSIONS

Bone-preserving hip replacement has increased in popularity as hip replacement in younger and more active individuals increases. The CFP prosthesis has excellent midterm clinical function and survival and provides high levels of satisfaction in young patients.

Biomechanics of a short stem: In vitro primary stability and stress shielding of a conservative cementless hip stem

Short stem prostheses provide conservative surgery and favorable metaphyseal load transmission. However, clinical long-term results are lacking. Therefore, in vitro trials can be used to predict bone-implant performance. In this in vitro study, primary stability and stress shielding of a new cementless short stem implant was evaluated in comparison to a straight stem using nine pairs of human cadaver femurs. Primary stability, including reversible micromotion and irreversible migration, was assessed in a hip simulator. Furthermore, changes in the pattern of cortical strain were evaluated. The short stem was more resistant to reversible micromotion and irreversible migration into retroversion. Axial stability was similar, with mean reversible micromotions of 9 µm for the short stem and 7 µm for the straight stem. Proximal load transmission was more physiological with the short stem, though both implants could not avoid stress shielding in Gruen zones 1 and 7. Primary stability of the short stem prosthesis was not negatively influenced compared to the straight shaft. Furthermore, proximal femoral strain pattern was more physiological after insertion of the short stem prosthesis.

Five-year results of a cementless short-hip-stem prosthesis

Hip prosthesis stems with a short stem length and proximal fixation geometry support a bone-preserving and muscle-sparing implantation and should also allow for revision surgery with a standard hip stem. We present 250 prospectively documented clinical and radiological results from the Metha Short Hip Stem prosthesis (B. Braun-Aesculap, Tuttlingen, Germany) after an average follow-up of 4.9 years. The average patient age at surgery was 60 years. Indication for total hip replacement was primary osteoarthrosis (OA) (78% of patients), OA based on developmental dysplasia of the hip (16%), and other indications (6%). At the last follow-up, the average Harris Hip Score was 97 points. 85% of patients were very satisfied and 14% were satisfied after surgery, whereas 1% were dissatisfied. Pain according to the Visual Analogue Scale improved from 7.4 (min 1.6, max 9.5) pre-operatively to 0.23 (min 0, max 6.6). No joint dislocations occurred when predominantly using 28 mm and 32 mm prosthesis heads. Nine short-stems were revised: three after bacterial infections, two after primary via valsa with penetration of the femoral cortex two and three months after surgery, and three after early aseptic cases of loosening within the first year. A further nine osseously consolidated short-stems had to be replaced due to breakage of the modular titanium cone adapter after an average of 3.1 years (min 1.9, max 4.4). All surgical revisions were performed using primary standard stems. Without taking the material-related adapter failures into account, a five year Kaplan-Meier survival rate of 96.7% (95% confidence interval 93.4–98.3) was determined for the short-stem prostheses. There were no radiological signs of loosening in any of the short-stem prostheses at the last examination. Fine sclerotic lines were detected in Gruen's AP zones 1 (19%) and 2 (10.5%), individual hypertrophies in zone 3 (3.5%), fine seams in zones 4 (5.5%) and 5 (4%), without pedestal formations in zone 4, clear cancellous bone compressions in zone 6 (97.5%), as well as single fine scleroses (1.5%) and atrophies (2.5%) in zone 7. The mid-term clinical results with periprosthetic bone remodeling and without radiological signs of loosening confirm this metaphyseal short-stem treatment and fixation concept and the possibility of revision surgery using standard hip stems. Long-term results must be further observed on a prospective basis as part of this collective study.

The influence of resection height on proximal femoral strain patterns after Metha short stem hip arthroplasty: an experimental study on composite femora

PURPOSE

The number of candidates for a total hip arthroplasty (THA) is steadily increasing, while the average patient age is decreasing for primary THA. The rise in THA is mainly due to excellent clinical outcomes and the extended longevity of modern implants. Short stem arthroplasties with predominantly metaphyseal fixation such as the Metha® stem are suggested for young patients. It is hypothesised that the more physiological load transfer of these devices reduces stress shielding, which in turn may reduce the risk of aseptic loosening. However, patients with femoral deformities often require a deviation of the resection height. To this end, our aim was to evaluate how resection height influences strain patterns in order to characterise possible limits for short stem implantation.

METHODS

Biomechanical testing using ten strain gauges on synthetic bone illustrated the strain patterns of three different resection heights (0, +5 and +10 mm) for the Metha stem.

RESULTS

The greatest differences in strains were displayed at the "high" (most proximal) resection height (+10 mm) when compared to the non-implanted strain pattern. At the medial calcar, the strain was 143% for +10 mm, 96% for +5 mm and 94% for 0 mm. Overall, discrepancies were less for deeper resections.

CONCLUSIONS

The deeper the resection, the more similar the strain patterns are when compared to a non-implanted synthetic bone. Changes in strain patterns are induced by variation in the varus/valgus positioning of the implant and by different offsets.

Revision of hip resurfacing arthroplasty with a bone-conserving short-stem implant: a case report and review of the literature

Introduction

Suitable treatment of early failure of total hip replacement is critical in younger patients, as bone stock is lost and the functional outcome is impaired.

Case presentation

We report the case of a 56-year-old Caucasian woman with early failure of hip resurfacing arthroplasty. While revision is usually performed with a conventional hip implant, this case report describes for the first time a revision procedure with a bone-conserving short-stem hip implant.

Conclusions

Our approach allows further conservation of femoral bone stock and provides a long-term solution to the patient, which maintains the possibility of using a conventional hip implant should a second revision become necessary.