The effect of posterior capsulorrhaphy in primary total hip arthroplasty: a prospective randomized study

Insufficient stem antetorsion and lower cup abduction is a combined risk factor for posterior hip dislocation in patients undergoing THA for femoral neck fractures: a retrospective analysis

BACKGROUND

The role of acetabular and femoral component positions with respect to the risk of post-operative instability and dislocation remains debated. In this study, we aimed to identify potential risk factors for early dislocation following primary total hip arthroplasty (THA) for displaced intracapsular femoral neck fractures (FNF) using radiological measurements.

METHODS

We retrospectively analyzed data for patients who underwent cementless primary THA for FNF using a posterolateral approach between January 2018 and December 2021. Follow-up duration, age, sex, affected side, and mean time from THA to dislocation were recorded. Leg-length inequality, abductor lever arm, vertical and horizontal femoral offsets, vertical and horizontal hip centers of rotation, abduction, anteversion of the acetabulum and femoral prosthesis, and combined anteversion were measured.

RESULTS

The study sample included 17 men and 34 women, with 21 and 30 patients undergoing left- and right-hip operations, respectively. The mean patient age was 70.18 ± 7.64 years, and the mean follow-up duration was 27.73 ± 13.52 months. The mean time between THA and dislocation was 1.58 ± 0.79 months. Seven patients (13.73%) sustained posterior dislocation of the hip. The abduction angle (36.05 ± 6.82° vs. 45.68 ± 8.78°) (p = 0.008) and anteversion of the femoral prosthesis (8.26 ± 4.47° vs. 19.47 ± 9.01°) (p = 0.002) were significantly lower in the dislocation group than in the control group. There were no significant differences in other parameters.

CONCLUSIONS

Insufficient stem antetorsion combined with lower abduction angle of the acetabular component were associated with a high risk of dislocation, especially in patients with deep flexion or internal rotation of the flexed hip joint and knees, or in patients with a stiff spine or anterior pelvic tilt, impingement may then occur in the neck of the prosthesis and cup component, ultimately resulting in posterior dislocation. These findings could remind surgeons to avoid simultaneous occurrence of both in THA surgery. These results provide new insight into risk factors for hip dislocation in patients undergoing primary THA for FNF and may aid in reducing the risk of instability and dislocation.

LEVEL OF EVIDENCE

Prospective comparative study Level II.

Is there any clinical advantage of capsular repair over capsular resection for total hip arthroplasty? An updated systematic review and meta-analysis

INTRODUCTION

Although several surgical approaches, with or without capsular repair, can be used during total hip arthroplasty (THA), there is no clear evidence that capsular repair provides a clinical advantage post-surgery, regardless of surgical approach. This systematic review and meta-analysis evaluated whether capsular repair using various surgical approaches provides a clinical advantage over capsular resection post-THA.

METHODS

This study was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) 2020 checklist for systematic reviews and meta-analyses. Multiple comprehensive literature searches were performed. Results were summarized qualitatively as meta-analysis of pooled odds ratios, and the standardized mean difference, with 95% confidence intervals for each group: capsular repair or capsular resection. A P value < 0.05 was considered statistically significant. Each study was evaluated for the risk of bias. Publication bias was also assessed.

RESULTS

A total of 12 studies were included after screening and eligibility assessment. The odds ratio for hip dislocation after capsular repair was 0.14 (P < 0.00001). The standard mean difference of the Harris Hip Score (HHS) after capsular repair was 1.11 (P = 0.02). There were no significant differences between groups with respect to operation time (P = 0.79) and blood loss (P = 0.42).

CONCLUSION

The current meta-analysis suggests that capsular repair leads to lower dislocation rates and a better HHS after THA.

Reducing Complications and Enhancing the Functional Outcome of Total Hip Arthroplasty without Increasing Operation Time by Repairing Posterolateral Soft Tissues

Total hip arthroplasty (THA) surgeries are increasing annually. Despite continuous improvements in the surgical technique and prosthetic design, there is still no consensus on whether it is beneficial to reconstruct the posterolateral soft tissue. This paper systematically reviews randomized controlled trials (RCTs) addressing the efficacy and safety of posterolateral soft tissue during total hip replacement to provide evidence-based guidance for clinical practice. We searched PubMed, EMBASE, Cochrane Library, CNKI, and Wanfang databases for RCTs. Experimental results show that repair of the posterolateral soft tissue can reduce complications and improve the function of total hip arthroplasty without increasing operative time.

Comparison of short-term outcomes of anterolateral supine approach and posterolateral approach for primary total hip arthroplasty: a retrospective study

Background

This study aims to evaluate postoperative pain and functional and clinical outcomes of anterolateral supine (ALS) and posterolateral (PL) approaches for primary total hip arthroplasty.

Materials and methods

We retrospectively examined the joints of 110 patients who underwent primary total hip arthroplasty (THA). The ALS group was compared with the PL group using the pain visual analog scale (VAS) and narcotic consumption as pain outcomes. Functional outcomes included postoperative range of motion (ROM) of hip flexion, day on which patients could perform straight leg raising (SLR), day on which patients began using a walker or cane, duration of hospital stay, rate of transfer, and strength of hip muscles. Clinical outcomes included pre and postoperative Harris Hip Scores.

Results

No significant differences were found in the pain VAS scores or narcotic consumption between the two groups. The PL group could perform SLR earlier than the ALS group (P < 0.01). The ALS group started using a cane earlier (P < 0.01) and had a shorter hospital stay (P < 0.01) than the PL group. Degrees of active ROM of flexion at postoperative day (POD) 1 were significantly lower in the ALS group than in the PL group (P < 0.01). Regarding hip muscle strength, hip flexion was significantly weaker in the ALS group than in the PL group until 1-month POD (P < 0.01). External rotation from 2 weeks to 6 months postoperatively was significantly weaker in the PL group than in the ALS group (P < 0.01).

Conclusion

The ALS approach was more beneficial than the PL approach because ALS enabled better functional recovery of the strength of external rotation, improved rehabilitation, and involved a shorter hospital stay.

Level of Evidence

Level IV retrospective observational study.

Minimally invasive posterolateral hip approach with SPARTAQUUS (Spare the Piriformis And Respect The Active QUadratus femoris and gluteus mediUS) technique

Interest in the different surgical approaches to total hip arthroplasty remains high, but without any real consensus on which approach is the most beneficial. Several recent technical innovations have made it possible to reduce the risk of dislocation, therefore improving the efficacy of the posterolateral approach. Since 2003, we have been using a modified minimally invasive posterolateral approach called SPARTAQUUS (Spare the Piriformis And Respect The Active QUadratus femoris and gluteus mediUS), which spares the piriformis tendon, the quadratus femoris muscle and the gluteus medius muscle, and involves direct capsular repair. The "active posterosuperior hammock" effect of the piriformis tendon is therefore coupled with the "passive posterosuperior hammock" effect of the capsular repair, thus limiting the risks of posterior dislocation of the prosthetic hip joint.

Transosseous versus transmuscular repair of the posterior soft tissue in primary hip arthroplasty: a meta-analysis

Background

During the posterior approach, it has been shown that a significant reduction in dislocation rate can be achieved with the repair of the posterior soft tissue. However, no consensus exists about the best way to perform this repair. This review aimed to compare the transosseous with transmuscular repair of the posterior soft tissue in total hip arthroplasty (THA).

Methods

We conducted a meta-analysis to identify studies involving transosseous versus transmuscular repair of the posterior soft tissue in THA in electronic databases, including Web of Science, Embase, PubMed, Cochrane Controlled Trials Register, Cochrane Library, Highwire, CBM, CNKI, VIP, Wanfang database, up to July 2020. Finally, we identified 1417 patients (1481 hips) assessed in seven studies.

Results

Compared with transmuscular repair, transosseous repair resulted in less incidence of dislocation (P = 0.003), less blood loss during operation (P < 0.00001) and lower VAS score within 3 months (P = 0.02). There were no significant differences in terms of trochanteric fracture rate (P = 0.56), Harris hip score at 3 months (P = 0.35) and 6 months (P = 0.89), VAS score within 6 months (P = 0.53), and operation time (P = 0.70) between two groups.

Conclusion

The lower dislocation rate, less blood loss, and lower VAS scores after operation supported transosseous repair's superiority to transmuscular repair. Besides, no additional medical cost and operating time were associated with transosseous repair compared with transmuscular repair. Hence, we recommend that transosseous repair be chosen first by orthopedists when performing reconstruction of the posterior soft tissue in THA via a posterolateral approach. Given the relevant possible biases in our meta-analysis, we required more adequately powered and better-designed RCT studies with long-term follow-up to reach a firmer conclusion.

The effect of posterior capsule repair in total hip arthroplasty: a systematic review and meta-analysis

Background

Prior studies have compared the posterior capsule repair group in primary total hip arthroplasty by posterior approach with the control group without posterior capsule repair suggesting that the posterior capsule repair group had better clinical outcomes. However, it is still a controversy which treatment is more helpful for hip diseases. The purpose of our article is to obtain the postoperative outcomes between the 2 procedures.

Methods

We performed a systematic search by browsing the MEDLINE, EMBASE, Cochrane Library. There is no restriction on the date of publication. Before we submit our manuscript, we have re-searched the literatures again, including the articles which directly compared the postoperative outcomes of the 2 procedures.

Results

A total of 8 comparative studies were included in our meta-analysis. The posterior capsule repair group showed less dislocation rate, higher HHS, and even less postoperative bleeding volume. Meanwhile, there is no significant difference in ROM between 2 groups.

Conclusion

In conclusion, according to current evidences, repairing posterior capsule during primary THA may have better functional outcomes, less dislocation incidence, and less loss of blood.

Prospective Evaluation of the Posterior Tissue Envelope and Anterior Capsule After Anterior Total Hip Arthroplasty

BACKGROUND

Femoral exposure for direct anterior approach (DAA) total hip arthroplasty (THA) invariably requires posterior soft tissue releases. Released posterior structures cannot be repaired. The purpose of this study is to describe the frequency and anatomic consequences of DAA THA posterior soft tissue releases and to compare the appearance of the anterior capsule between a group of patients who had capsulotomy and repair versus capsulectomy.

METHODS

Thirty-two DAA THA patients underwent metal artifact reduction sequence magnetic resonance imaging at discharge and 1-year follow-up. Seventeen had underwent capsulotomy and repair and 15 capsulectomy. A radiologist blinded to intraoperative data scored each metal artifact reduction sequence magnetic resonance imaging. Anterior capsular integrity, status of the piriformis and conjoint tendons, and muscle atrophy were graded. Descriptive statistics were performed to analyze results.

RESULTS

Immediately postoperatively, 75% of piriformis tendons were intact and 38% of conjoined tendons were intact. At 1 year, 97% had an intact piriformis and conjoined tendon, although many were in continuity through scar with the capsule. The posterior capsule directly contacted bone in all patients. At 1 year, none of the patients who underwent capsulotomy with repair had persistent anterior capsule defects, while 27% in the capsulectomy group had persistent defects.

CONCLUSION

Posterior capsule and conjoined tendon releases were commonly performed during DAA THA, yet continuity with bone was frequently achieved at 1 year. In this study, capsulotomy with repair resulted in no anterior capsular defects when compared with capsulectomy. These results may support improved THA stability observed after DAA with capsular repair despite posterior soft tissue releases.

LEVEL OF EVIDENCE

Level III, prospective cohort study.

Total hip arthroplasty without subtrochanteric femoral osteotomy is possible in patients with Crowe III/IV developmental dysplasia: total hip arthroplasty without femoral osteotomy

BACKGROUND

We aimed to present our THA technique without femoral shortening osteotomy that we perform for the treatment of coxarthrosis on Crowe type III/IV developmental dysplasia of the hip and to present the early clinical outcomes of our patients.

METHODS

77 patients with Crowe type III/IV developmental dysplasia of the hip, who had admitted to our clinic between 2013 and 2017, and had undergone cementless THA without femoral shortening by a single surgeon, were retrospectively evaluated. Patients were called for a final evaluation and assessed by Harris Hip Score. Trendelenburg sign was observed. For radiological evaluation, routine anteroposterior and lateral hip radiography and orthoroentgenogram was used.

RESULTS

Mean duration of follow-up was 38.2 (22-52) months. Pre-operative mean Harris Hip Score was 53.9 (49-62) and post-operative mean value was 82.7 (76-95). Mean duration of operation was 44.9 (39-57) min. In post-operative final evaluation only three patients (3.8%) had positive Trendelenburg sign. 3 patients (3.8%) had early dislocation. No sciatic palsy was observed in any of the patients. Revision with acetabular cage was performed for one (1.2%) patient due to protrusion development in the acetabular cup. The mean prosthesis survival rate was 98.8%.

CONCLUSIONS

Total hip arthroplasty without femoral osteotomy can be considered as a successful method in selected patients with Crowe III/IV coxarthrosis. It provides good clinical outcomes in the early period, reduces surgery duration, has acceptable complication rates, has high prosthesis survival rates.

Patient satisfaction in different approaches for total hip arthroplasty

BACKGROUND

At present, the posterolateral, the direct lateral and direct anterior approach (DAA) are the most frequently used techniques for total hip arthroplasty (THA), however there is no clear superiority of one of the approaches based on clinical outcome measures. The goal of this study is to lead the patient and the surgeon to an optimal treatment by providing them with relevant information based on patient reported outcome measures (PROMs).

METHODS

Patient satisfaction and hip function one year postoperatively were investigated retrospectively in a cohort of patients who underwent hip replacement surgery by DAA on one hip and by posterolateral or direct lateral approach on the contralateral hip. Additionally, a control group who underwent the DAA bilaterally was used for comparison.

RESULTS

No difference in hip function was found between the DAA and the posterolateral or direct lateral approach, measured with the Hip disability and Osteoarthritis Outcome Score (HOOS) questionnaire at least one year postoperatively to the last THA in the study group. Also in the control group no difference was found between the hips. However, the overall scores of the control group were higher, although not statistically significant, than those of the study group (p=0.055). And a majority of the study group preferred the DAA (68%), with the reasons reported being faster recovery, less sleeping disturbance and earlier mobilization.

CONCLUSION

As expected, the postoperative hip function is similar, but patients' preference is not. The latter result might be true or possibly influenced by preoperative psychological factors and mental health. The DAA and the posterolateral or direct lateral approaches have shown to lead to a similar hip function, but a majority of patients subjectively prefer the DAA.

LEVEL OF EVIDENCE

III.

Effect of articular capsule repair on postoperative dislocation after primary total hip replacement by the anterolateral approach

Objective

Artificial hip dislocation is one of the most serious complications following total hip replacement. This study was performed to assess articular capsule repair in primary total hip replacement with the anterolateral approach (Watson-Jones incision) and its effect on postoperative dislocation.

Methods

Patients who underwent primary total hip replacement by the anterolateral approach in Tongren Hospital of Shanghai Jiao Tong University School of Medicine from June 2007 to June 2014 were retrospectively analyzed. The patients were divided into the repair and dissection groups based on the articular capsule repair status during surgery. Postoperative dislocation rates were compared between the two groups using the chi-squared test.

Results

The repair and dissection groups comprised 137 and 248 patients, respectively. All patients were followed up for 6 months to 5 years (average, 3.75 years). The mean age, sex, disease composition, and follow-up time were not significantly different between the two groups. Early postoperative dislocation occurred in 1 hip (0.7%) in the repair group and 13 hips (5.2%) in the dissection group.

Conclusions

During the anterolateral approach for primary total hip replacement, articular capsule repair may reduce the occurrence of early postoperative dislocation of the hip joint.

Early dislocation in primary total hip arthroplasty using a posterior approach with repair of capsule and external rotators

OBJECTIVE

To determine the incidence of dislocation after primary total hip arthroplasty using a posterior approach with repair of capsule and transosseous external rotators.

MATERIAL AND METHOD

Historical cohort study between January 2009 and December 2015 of all the cases of dislocation of primary total hip arthroplasty operated using a posterior approach with repair of capsule and transosseous external rotators. Demographic and clinical data concerning the patient, surgery and dislocation were collected and analyzed. A descriptive analysis and a study of survival and risk function were performed by Kaplan Meier's method considering the appearance of a hip dislocation as the final event.

RESULTS

The incidence of dislocation in our study was 1.2% (23 patients). In our study, the highest probability of dislocation occurred in the first 120 days. Forty-three point 5percent of the dislocated patients needed revision surgery.

CONCLUSIONS

Capsular repair and transosseous reattachment of the external rotators can help to reduce the incidence of dislocation in patients undergoing primary total hip arthroplasty through a posterior approach.

Preservation technique of the piriformis tendon is superior to reattachment technique in terms of contiguity and muscle atrophy: using magnetic resonance imaging

PURPOSE

The preservation technique of the piriformis tendon during the posterolateral approach in total hip arthroplasty (THA) is reportedly superior to the reattachment technique in terms of dislocation. However, the long-term effects of preservation of the piriformis tendon during THA remain unknown. In this study, we evaluated the contiguity of the piriformis/conjoined tendon and atrophy of the piriformis/internal obturator muscle during a long-term postoperative follow-up using magnetic resonance imaging (MRI).

METHODS

We retrospectively evaluated 48 patients with available MRI. The 48 patients were classified into a P group ( n = 29), in which the piriformis tendon was preserved, and an R group ( n = 19), in which the piriformis was reattached after sectioning. The mean follow-up duration was 45.9 months. The contiguity of the piriformis/conjoined tendon and atrophy of the piriformis/internal obturator muscle were evaluated in all patients.

RESULTS

The piriformis tendon remained attached to the greater trochanter in all P-group patients and 68.4% of R-group patients. The mean piriformis muscle atrophy ratios were 15.9% ± 21.1% in the P group and 41.6% ± 19.1% in the R group ( p < 0.001). The conjoined tendon repair remained intact in 72.4% of P-group patients and 36.8% of R-group patients ( p < 0.05). The mean internal obturator muscle atrophy ratio was 31.4% ± 26.2% in the P group and 50.4% ± 19.1% in the R group ( p < 0.05). No postoperative pulmonary embolism, wound infection, deep infection, or hip dislocation occurred.

CONCLUSIONS

In our study, we suggest that the preservation technique of the piriformis tendon is superior to the reattachment technique in terms of contiguity and muscle atrophy.

Variation in Use of Postoperative Precautions and Equipment Following Total Hip Arthroplasty: A Survey of the AAHKS and CAS Membership

BACKGROUND

A traditional method to reduce dislocation risk following total hip arthroplasty involves prescribing postoperative precautions and ambulatory equipment to patients. The purpose of this study was to determine the prevalence of postoperative precaution and equipment use among North American arthroplasty surgeons for patients undergoing primary total hip arthroplasty.

METHODS

We conducted a survey of American Association of Hip and Knee Surgeons and Canadian Arthroplasty Society members using an electronic questionnaire format to determine how often precautions and equipment were prescribed, and whether their use was associated with surgical approach and other surgeon demographics.

RESULTS

Of the respondents, 44% universally prescribed precautions while 33% never prescribed precautions. Use of the posterolateral approach, surgeon experience, and larger head size use were significantly associated (P < .01) with precaution and equipment use. Direct anterior approach surgeons were significantly less likely to prescribe precautions (P < .0001) and significantly less likely to prescribe equipment (P < .0001).

CONCLUSION

Although postoperative precautions continue to be used to some degree by the majority of members, their consumption of healthcare resources through utilization of additional care providers and purchasing of equipment, known association with reduced patient satisfaction, and lack of supporting evidence make them a target for future scrutiny.

Capsular Ligament Function After Total Hip Arthroplasty

BACKGROUND

The hip joint capsule passively restrains extreme range of motion, protecting the native hip against impingement, dislocation, and edge-loading. We hypothesized that following total hip arthroplasty (THA), the reduced femoral head size impairs this protective biomechanical function.

METHODS

In cadavers, THA was performed through the acetabular medial wall, preserving the entire capsule, and avoiding the targeting of a particular surgical approach. Eight hips were examined. Capsular function was measured by rotating the hip in 5 positions. Three head sizes (28, 32, and 36 mm) with 3 neck lengths (anatomical 0, +5, and +10 mm) were compared.

RESULTS

Internal and external rotation range of motion increased following THA, indicating late engagement of the capsule and reduced biomechanical function (p < 0.05). Internal rotation was affected more than external. Increasing neck length reduced this hypermobility, while too much lengthening caused nonphysiological restriction of external rotation. Larger head sizes only slightly reduced hypermobility.

CONCLUSIONS

Following THA, the capsular ligaments were unable to wrap around the reduced-diameter femoral head to restrain extreme range of motion. The posterior capsule was the most affected, indicating that native posterior capsule preservation is not advantageous, at least in the short term. Insufficient neck length could cause capsular dysfunction even if native ligament anatomy is preserved, while increased neck length could overtighten the anterior capsule.

CLINICAL RELEVANCE

Increased understanding of soft-tissue balancing following THA could help to prevent instability and improve early function. This study illustrates how head size and neck length influence the biomechanical function of the hip capsule in the early postoperative period.

Posterior hip approach yields better functional results vis-à-vis anterolateral approach in total hip arthroplasty for patients with severe hip dysplasia: A prospective randomized controlled clinical study

OBJECTIVES

We aimed to compare functional outcomes of two common hip approaches for patients with severe hip dysplasia in total hip replacement (THR) surgery.

MATERIALS AND METHODS

Seventy hips of 68 patients randomized into two groups with regard to hip approach as posterior (group I) and anterolateral (group II). All patients underwent THR surgery with femoral shortening osteotomy. The groups were compared for operation time, preoperative and 6 months after abductor muscle strengths (AMSs), gait disorders, union time of the osteotomied site and dislocation rates.

RESULTS

There were two early dislocations in group I, and two early and one late dislocations in group II. No significant difference was observed regarding hip dislocations. Mean union time of the osteotomied site was 113.9 ± 51 days in group I while 111.1 ± 29.3 days in group II ( p = 0.774). Six months after surgery, group I had higher AMS than group II ( p < 0.0001). More patients in group II had Trendelenburg gait pattern ( p = 0.043), while no difference was observed regarding antalgic and deviated gait patterns between groups.

CONCLUSION

THR surgery for patients with severe developmental dysplasia of hip is a challenging procedure, and posterior approach provides better functional outcomes regarding gait and AMSs.

Is soft tissue repair a right choice to avoid early dislocation after THA in posterior approach?

Background

Dislocation is the second most common complication after total hip arthroplasty (THA). The effectiveness of soft tissue repair to reduce dislocation rate is still debated and thus a meta-analysis was conducted.

Methods

A systematic search in PubMed, Embase, and Cochrane databases was conducted for this meta-analysis. Inclusion criteria: clinical comparative trials on the use of soft tissue repair including rotators and capsule repair in primary THA. The main data outcome were the incidences of early hip dislocation after primary THA. HSS score, incidence of other complications was also included in the outcomes.

Results

A total of 4816 cases were included for the analysis from ten studies (3 RCTs/7 Retrospective trials). Overall, the soft tissue repair group showed a significant lower early dislocation rate and higher HSS score compared to the no repair group; but no significant difference was observed between the two groups in regards to the early dislocation rate in RCT studies only. The capsule repair group showed a significant lower early dislocation rate than no capsule repair group while no significant difference was observed between the rotators repair group and no rotators repair group. In all included studies, 4 greater trochanter fractures, 2 sciatic nerve palsies and 1 infection were reported in soft tissue repair group while no cases were observed in the no repair group.

Conclusions

The efficacy of soft tissue repair is positive but still not conclusive to reduce the early dislocation rate after primary THA while soft tissue repair may bring more other complications. Capsule repair seems more effective than rotators repair only.

The result of transmuscular versus transosseous repair of the posterior capsule on early dislocations in primary hip arthroplasty

PURPOSE

Dislocation is a concerning complication of the posterolateral approach for total hip arthroplasty (THA). Use of a larger size femoral head and a correct repair of the posterior structures can reduce the risk on dislocation of the hip prosthesis. In this study we investigated if there was a difference in dislocation rate between transmuscular and transosseous repair of the posterior soft tissues with use of 36 mm heads.

METHODS

A power analysis showed that with a standardised effect size of 0.3 and p-value of 0.05, each group should include at least 174 patients. A total of 465 consecutive primary THAs with a posterolateral approach were performed in patients with primary osteoarthritis by 3 orthopaedic surgeons. There were 246 patients operated using transmuscular repair, the other 219 by using transosseous repair. All patients were given the same prostheses.

RESULTS

Dislocation rate was 1.7% in all patients with at least 1 year follow-up. No significant difference was found in dislocation between both reconstruction techniques. Clinical outcome scores were comparable between the groups.

CONCLUSIONS

Transosseous and transmuscular repair were equally effective techniques in closing the posterior soft tissues after THA through the posterolateral approach, without difference in dislocation rate or complication rate.

The Stress-Strain Data of the Hip Capsule Ligaments Are Gender and Side Independent Suggesting a Smaller Contribution to Passive Stiffness

Background

The ligaments in coherence with the capsule of the hip joint are known to contribute to hip stability. Nevertheless, the contribution of the mechanical properties of the ligaments and gender- or side-specific differences are still not completely clear. To date, comparisons of the hip capsule ligaments to other tissues stabilizing the pelvis and hip joint, e.g. the iliotibial tract, were not performed.

Materials & Methods

Hip capsule ligaments were obtained from 17 human cadavers (9 females, 7 males, 13 left and 8 right sides, mean age 83.65 ± 10.54 years). 18 iliofemoral, 9 ischiofemoral and 17 pubofemoral ligaments were prepared. Uniaxial stress-strain properties were obtained from the load-deformation curves before the secant elastic modulus was computed. Strain, elastic modulus and cross sections were compared.

Results

Strain and elastic modulus revealed no significant differences between the iliofemoral (strain 129.8 ± 11.1%, elastic modulus 48.8 ± 21.4 N/mm²), ischiofemoral (strain 128.7 ± 13.7%, elastic modulus 37.5 ± 20.4 N/mm²) and pubofemoral (strain 133.2 ± 23.7%, elastic modulus 49.0 ± 32.1 N/mm²) ligaments. The iliofemoral ligament (53.5 ± 15.1 mm²) yielded a significantly higher cross section compared to the ischiofemoral (19.2 ± 13.2 mm²) and pubofemoral (15.2 ± 7.2 mm²) ligament. No significant gender- or side-specific differences were determined. A comparison to the published data on the iliotibial tract revealed lower elasticity and less variation in the ligaments of the hip joint.

Conclusion

Comparison of the mechanical data of the hip joint ligaments indicates that their role may likely exceed a function as a mechanical stabilizer. Uniaxial testing of interwoven collagen fibers might lead to a misinterpretation of the mechanical properties of the hip capsule ligaments in the given setup, concealing its uniaxial properties. This underlines the need for a polyaxial test setup using fresh and non-embalmed tissues.

Tensile properties of the hip joint ligaments are largely variable and age-dependent - An in-vitro analysis in an age range of 14-93 years

INTRODUCTION

Hip joint stability is maintained by the surrounding ligaments, muscles, and the atmospheric pressure exerted via these structures. It is unclear whether the ligaments are capable of preventing dislocation solely due to their tensile properties, and to what extent they undergo age-related changes. This study aimed to obtain stress-strain data of the hip ligaments over a large age range.

METHODS

Stress-strain data of the iliofemoral (IL), ischiofemoral (IS) and pubofemoral ligament (PF) were obtained from cadavers ranging between 14 and 93 years using a highly standardized setting. Maximum strains were compared to the distances required for dislocation.

RESULTS

Elastic modulus was 24.4 (IL), 22.4 (IS) and 24.9N/mm² (PF) respectively. Maximum strain was 84.5%, 86.1%, 72.4% and ultimate stress 10.0, 7.7 and 6.5N/mm² for the IL, IS and PF respectively. None of these values varied significantly between ligaments or sides. The IS' elastic modulus was higher and maximum strain lower in males. Lower elastic moduli of the PF and higher maximum strains for the IS and PF were revealed in the ≥55 compared to the <55 population. Maximum strain exceeded the dislocation distance of the IS without external hip joint rotation in females, and of the IS and cranial IL under external rotation in both genders.

DISCUSSION

Tensile and failure load properties of the hip joint ligaments are largely variable. The IS and PF change age-dependently. Though the hip ligaments contribute to hip stability, the IS and cranial IL may not prevent dislocation due to their elasticity.

Arthroscopic Capsular Reconstruction of the Hip With Acellular Dermal Extracellular Matrix: Surgical Technique

Atraumatic instability of the hip has become an increasingly studied occurrence in recent years. There are several established surgical techniques that help restore stability of the native hip joint. In some cases, these procedures are not an option. As the phenomenon has become recognized more frequently, a greater number of revision surgeries are warranted in patients with ligamentous laxity. A durable solution for irreparable microinstability needs to be formulated to address this vulnerable patient demographic. We describe the surgical technique for capsular reconstruction with acellular dermal extracellular matrix.

Does Surgical Approach Affect Patient-reported Function After Primary THA?

BACKGROUND

Total hip arthroplasty (THA) relieves pain and improves physical function in patients with hip osteoarthritis, but requires a year or more for full postoperative recovery. Proponents of intermuscular surgical approaches believe that the direct-anterior approach may restore physical function more quickly than transgluteal approaches, perhaps because of diminished muscle trauma. To evaluate this, we compared patient-reported physical function and other outcome metrics during the first year after surgery between groups of patients who underwent primary THA either through the direct-anterior approach or posterior approach.

QUESTIONS/PURPOSES

We asked: (1) Is a primary THA using a direct-anterior approach associated with better patient-reported physical function at early postoperative times (1 and 3 months) compared with a THA performed through the posterior approach? (2) Is the direct-anterior approach THA associated with shorter operative times and higher rates of noninstitutional discharge than a posterior approach THA?

METHODS

Between October 2008 and February 2010, an arthroplasty fellowship-trained surgeon performed 135 THAs. All 135 were performed using the posterior approach. During that period, we used this approach when patients had any moderate to severe degenerative joint disease of the hip attributable to any type of arthritis refractory to nonoperative treatment measures. Of the patients who were treated with this approach, 21 (17%; 23 hips) were lost to followup, whereas 109 (83%; 112 hips) were available for followup at 1 year. Between February and September 2011, the same surgeon performed 86 THAs. All 86 were performed using the direct-anterior approach. During that period, we used this approach when patients with all types of moderate to severe degenerative joint disease had nonoperative treatment measures fail. Of the patients who were treated with this approach, 35 (41%; 35 hips) were lost to followup, whereas 51 (59%; 51 hips) were available for followup at 1 year. THAs during the surgeon's direct-anterior approach learning period (February 2010 through January 2011) were excluded because both approaches were being used selectively depending on patient characteristics. Clinical outcomes included operative blood loss; allogeneic transfusion; adverse events; patient-reported Veterans RAND-12 Physical (PCS) and Mental Component Summary (MCS) scores, and University of California Los Angeles (UCLA) activity scores at 1 month, 3 months, and 1 year after surgery. Resource utilization outcomes included operative time, length of stay, and discharge disposition (home versus institution). Outcomes were compared using logistic and linear regression techniques.

RESULTS

After controlling for relevant confounding variables including age, sex, and BMI, the direct-anterior approach was associated with worse adjusted MCS changes 1 and 3 months after surgery (1-month score change, -9; 95% CI, -13 to -5; standard error, 2), compared with the posterior approach (3-month score change, -9; 95% CI, -14 to -3; standard error, 3) (both p < 0.001), while the direct-anterior approach was associated with greater PCS improvement at 3 months compared with the posterior approach (score change, 6; 95% CI, 2-10; standard error, 2; p = 0.008). There were no differences in adjusted PCS at either 1 month or 12 months, and no clinically important differences in UCLA scores. Although the PCS score differences are greater than the minimum clinically important difference of 5 points for this endpoint, the clinical importance of such a small effect is questionable. At 1 year after THA, there were no intergroup differences in self-reported physical function, although both groups had significant loss-to-followup at that time. Operative time (skin incision to skin closure) between the two groups did not differ (81 versus 79 minutes; p = 0.411). Mean surgical blood loss (403 versus 293 mL; p < 0.001; adjusted, 119 more mL; 95% CI, 79-160; p < 0.001) and in-hospital transfusion rates (direct-anterior approach, 20% [17/86] versus posterior approach, 10% [14/135], p = 0.050; adjusted odds ratio, 3.6; 95% CI, 1.3-10.1; p = 0.016) were higher in the direct-anterior approach group. With the numbers available, there was no difference in the frequency of adverse events between groups when comparing intraoperative complications, perioperative Technical Expert Panel complications, and other non-Technical Expert Panel complications within 1 year of surgery, although this study was not adequately powered to detect differences in rare adverse events.

CONCLUSIONS

With suitable experience, the direct-anterior approach can be performed with expected results similar to those of the posterior approach. There may be transient and small benefits to the direct-anterior approach, including improved physical function at 3 months after surgery. However, the greater operative blood loss and greater likelihood of blood transfusions, even when the surgeon is experienced, may be a disadvantage. Given some of the kinds of bias present that we found, including loss to followup, the conclusions we present should be considered preliminary, but it appears that any benefits that accrue to the patients who had the direct-anterior approach would be transient and modest. Prospective randomized studies on the topic are needed to address the differences between surgical approaches more definitively.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Surgical approach in primary total hip arthroplasty: anatomy, technique and clinical outcomes

Total hip arthroplasty (THA) has revolutionized the treatment of hip arthritis. A number of surgical approaches to the hip joint exist, each with unique advantages and disadvantages. The most commonly used approaches include the direct anterior, direct lateral and posterior approaches. A number of technical intricacies allow safe and efficient femoral and acetabular reconstruction when using each approach. Hip dislocation, abductor insufficiency, fracture and nerve injury are complications of THA, although their relative risk varies by approach. Numerous clinical trials have sought to elicit differences in patient-reported outcomes, complication rates and return to function among the surgical approaches. This review outlines some of the technical pearls of performing a THA through either a direct anterior, direct lateral or posterior approach. A literature review outlines the impact of surgical approach on clinical outcomes and clinically relevant complication rates.

Capsule repair may reduce dislocation following hip hemiarthroplasty through a direct lateral approach: a cadaver study

Reported rates of dislocation in hip hemiarthroplasty (HA) for the treatment of intra-capsular fractures of the hip, range between 1% and 10%. HA is frequently performed through a direct lateral surgical approach. The aim of this study is to determine the contribution of the anterior capsule to the stability of a cemented HA through a direct lateral approach. A total of five whole-body cadavers were thawed at room temperature, providing ten hip joints for investigation. A Thompson HA was cemented in place via a direct lateral approach. The cadavers were then positioned supine, both knee joints were disarticulated and a digital torque wrench was attached to the femur using a circular frame with three half pins. The wrench applied an external rotation force with the hip in extension to allow the hip to dislocate anteriorly. Each hip was dislocated twice; once with a capsular repair and once without repairing the capsule. Stratified sampling ensured the order in which this was performed was alternated for the paired hips on each cadaver. Comparing peak torque force in hips with the capsule repaired and peak torque force in hips without repair of the capsule, revealed a significant difference between the 'capsule repaired' (mean 22.96 Nm, standard deviation (sd) 4.61) and the 'capsule not repaired' group (mean 5.6 Nm, sd 2.81) (p < 0.001). Capsular repair may help reduce the risk of hip dislocation following HA.

Effectiveness and safety of the posterior approach with soft tissue repair for primary total hip arthroplasty: a meta-analysis

BACKGROUND

Repair of soft tissue in favour of the posterior approach for total hip arthroplasty is still under discussion and few studies are assessing this issue. Therefore, we performed a meta-analysis to compare the effectiveness and safety of the posterior approach for total hip arthroplasty with and without soft tissue repair. We focused on these questions as follows: does primary posterior approach for total hip arthroplasty with soft tissue repair has better result regarding dislocation rate, Harris hip score and the sciatic nerve palsy rate compared with posterior approach without soft tissue repair.

PATIENTS AND METHODS

We conducted electronic literature searches using CENTRAL (Issue 1 of 12, Jan 2014), PUBMED (1980 to Jan 2014), and EMBASE (1980 to Jan 2014). Clinical studies evaluating the posterior approach for total hip arthroplasty with and without soft tissue repair were collected. After independent study selection by 2 authors, data were collected and extracted independently. The methodological quality of the studies was assessed by the Cochrane Collaboration's tool for assessing risk of bias and the Newcastle-Ottawa Scale.

RESULT

Seven clinical trials with 4594 hips using the posterior approach for total hip arthroplasty were included. The pooled data indicated a lower rate of dislocation (OR: 0.14, 95% CI: 0.08-0.26, P<0.00001) and higher Harris hip score (1.75, 95% CI: 1.19 to 2.32, P<0.00001, I(2)=26%) after the posterior approach to total hip arthroplasty using soft tissue repair than without using soft tissue repair. There was no statistical difference in sciatic nerve palsy between the use of soft tissue repair and without it in posterior approach to total hip arthroplasty (OR: 5.34, 95% CI: 0.25-112.25, P=0.28).

DISCUSSION

Our meta-analysis included data from more studies than were previously available and demonstrated that the use of soft tissue repair and without it in posterior approach to total hip arthroplasty are similar in safety. Using repair resulted in a lower dislocation rate and higher Harris hip score than without repair.

LEVELS OF EVIDENCE

Level 2 meta-analysis of low-powered prospective randomised trial.

Hip dislocations after 2,734 elective unilateral fast-track total hip arthroplasties: incidence, circumstances and predisposing factors

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

To investigate the incidence of hip dislocation 90 days after total hip arthroplasty in relation to time after surgery, mechanism of dislocation and predisposing factors.

METHODS

Prospective data on preoperative patient characteristics from six Danish arthroplasty departments with similar fast-track approaches were cross-referenced with the Danish National Patient Registry for complete 90-day follow-up on readmissions, including emergency-room contacts. Complete patient files and postoperative radiographs were reviewed in case of dislocations. Unadjusted comparisons were made using t test/Chi-square analyses, while evaluation of risk factors potentially predisposing to dislocations was done using uni- and multivariate regression analysis.

RESULTS

A total of 2,734 consecutive unselected procedures were available for analysis, of which 65 (2.4 %) had dislocations. Of these, eight were during index admission and five were treated and discharged from the emergency room. Mechanisms of dislocation were most often movement while supine or sitting for the first 30 days and due to squatting/bending from day 31 to 90. The 65 patients with dislocations had suboptimal cup placement in 34 (52.3 %), and a femoral head size of <36 mm in 20 (30.8 %) cases. Predisposing factors of dislocation were age ≥75 [OR:1.96 (1.18-3.38)], pharmacologically treated psychiatric disease [OR:2.37 (1.29-4.36)] and department of surgery [OR:2.27 (1.31-3.40)] but not hospital stay of <4 days. Departments with recommendations for activity restrictions had fewer dislocations than a department without restrictions.

CONCLUSIONS

Patients ≥75 years and with pharmacologically treated psychiatric disease may be at increased risk of dislocations after fast-track total hip arthroplasty. Further studies including detailed information on patient and prosthesis characteristics, and activity restrictions are needed to reduce the risk of dislocation.

Modified posterior soft tissue repair for the prevention of early postoperative dislocation in total hip arthroplasty

PURPOSE

Dislocation following total hip arthroplasty (THA) with the posterior approach has been quite a common and bothering complication. Previous researches suggest that careful repair of the posterior structures significantly reduces this risk. The purposes of the present study were to describe a modified posterior soft tissue repair procedure in THA using a suture anchor (TwinFix Ti 5.0, Smith & Nephew, Andover, MA) and evaluate the early postoperative dislocation rate.

METHODS

From July 2004 to June 2008, 220 consecutive primary total hip arthroplasties were performed using the modified surgical approach. The average age in the group was 46.4 years (range from 21 to 90) at the time of the procedure. The rate of postoperative hip dislocation, as well as any signs of complications related to the technique, has been observed and analyzed in this study.

RESULTS

There was no postoperative dislocation following primary THA in 220 cases, and no signs of complications related to the technique, such as greater trochanteric fractures and sciatic nerve palsy, have been noted in any of the cases at their most recent follow-up.

CONCLUSIONS

These initial results demonstrate that the modified repair in THA using the suture anchor can serve as an effective and reliable mean for prevention of early postoperative dislocation.

Arthroscopic capsulotomy, capsular repair, and capsular plication of the hip: relation to atraumatic instability

PURPOSE

The purpose of this systematic review was to critically evaluate the available literature exploring the role of the hip joint capsule in the normal state (stable) and pathologic states (instability or stiffness). Furthermore, we examined the various ways that arthroscopic hip surgeons address the capsule intraoperatively: (1) capsulotomy or capsulectomy without closure, (2) capsulotomy with closure, and (3) capsular plication.

METHODS

Two independent reviewers (B.D.G. and B.G.D.) performed a systematic review of the literature using PubMed and the reference lists of related articles by means of defined search terms. Relevant studies were included if these criteria were met: (1) written in English, (2) Levels of Evidence I to V, (3) focus on capsule and its role in hip stability, and (4) human studies and reviews. Articles were excluded if they evaluated (1) total hip arthroplasty constructs using bony procedures or prosthetic revision, (2) developmental dysplasia of the hip where reorientation osteotomies were used, (3) syndromic instability, and (4) traumatic instability with associated bony injury.

RESULTS

By use of the search method described, 5,085 publications were reviewed, of which 47 met appropriate criteria for inclusion in this review. Within this selection group, there were multiple publications that specifically addressed more than 1 of the inclusion criteria. Relevant literature was organized into the following areas: (1) capsular anatomy, biomechanics, and physiology; (2) the role of the capsule in total hip arthroplasty stability; (3) the role of the capsule in native hip stability; and (4) atraumatic instability and capsulorrhaphy.

CONCLUSIONS

As the capsuloligamentous stabilizers of the hip continue to be studied, and their role defined, arthroscopic hip surgeons should become facile with arthroscopic repair or plication techniques to restore proper capsular integrity and tension when indicated.

LEVEL OF EVIDENCE

Level IV, systematic review.

Magnetic resonance imaging features of preserved vs divided and repaired piriformis during total hip arthroplasty: a randomized controlled trial

The aim of this study was to compare the muscle grade and bulk of the divided and repaired piriformis tendon by the standard posterior approach with the preserved tendon by a piriformis-sparing (PS) approach, in total hip arthroplasty. Twenty-two patients were randomized to either approach. Patients received preoperative and 3 months and 2 years postoperative magnetic resonance imaging scans. Patients and evaluators were blinded to allocation. There was significantly less deterioration in piriformis muscle grade (P = .029) and bulk (P = .015) in the PS group at 3 months. At 2 years, only the difference in grade remained significant (P = .001). There was no difference in Oxford hip scores. In conclusion, a PS approach avoids the marked wasting and deterioration in muscle grade that occurs postoperatively in the standard posterior approach.

Surgical technique: a simple soft-tissue-only repair of the capsule and external rotators in posterior-approach THA

BACKGROUND

Posterior soft tissue repair after posterior THA reportedly decreases the risk of dislocation. Previously described techniques often require drill holes through the greater trochanter, do not include both the short external rotators and the capsule, or require a complex series of multiple sutures. We therefore describe a technique to address these issues.

DESCRIPTION OF TECHNIQUE

The posterior soft tissues were repaired with a single nonabsorbable suture passed through the external rotators and posterior capsule and then through the capsule and posterior border of minimus in a figure-of-eight pattern. This repair remains pliable and obliterates the dead space.

METHODS

We retrospectively reviewed 165 patients who underwent 178 primary THAs through a mini-posterior THA and also underwent soft tissue repair using our technique. We determined the rate of dislocation and complications associated with this technique. The minimum clinical followup was 1 year (mean, 23 months; range, 12-37 months).

RESULTS

This repair was associated with a low risk of dislocation at 1 year (one of 178 hips, 0.56%) and no apparent complications related to the technique.

CONCLUSIONS

This soft tissue to soft tissue repair technique after posterior-approach THA is technically straightforward and reliable with a low associated dislocation rate.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

The posterior approach in THR: assuring capsular stability

Repair of the posterior capsule is advocated to reduce dislocation after total hip replacement (THR). To date, no predictable physical findings are reported in the literature to assess the capsular integrity and risk of hip dislocation after the posterior approach. The internal rotation test is performed at 4 to 6 weeks postoperatively with the hip and knee flexed at 90° while the patient is supine. The test is positive if a firm endpoint is felt with internal rotation of ≤15°. Between January 2007 and January 2008, twenty-three patients who had magnetic resonance imaging (MRI) at a mean 1.8±0.7 years after posterior-approach THR were included in this study. Magnetic resonance images were reviewed by a blinded radiologist for the integrity of the posterior capsule and quadratus, the distance between the piriformis and conjoined tendon to bone, and the amount of piriformis obturator internus atrophy. Magnetic resonance imaging results in patients with positive internal rotation tests showed an intact posterior capsule and scarring of the tendons with no severe muscle atrophy. In patients with a negative internal rotation test, MRI showed incomplete healing of the tendons and severe muscle atrophy. Sensitivity and specificity of the internal rotation test for tendon/scar healing were 100% and 93%, respectively. The internal rotation test is a simple, reproducible test that, if positive, has a high correlation with capsule/tendon healing.

Achilles allograft reconstruction for recurrent dislocation in total hip arthroplasty

Recurrent dislocation secondary to posterior soft tissue deficiency is a challenging complication of total hip arthroplasty. We describe the use of an Achilles allograft sling to improve hip stability. Eight patients treated with the sling were followed an average of 5 years. Seven patients had no recurrent instability and good postoperative range of motion. One graft failed in a patient with a neuropathic hip. Cadaveric biomechanical testing was also performed to investigate the stiffness and torque to failure of the sling in 6 specimens. Allograft slings can be used to improve hip stability. The technique is relatively easy to perform and does not limit postoperative range of motion. The graft decreases joint stiffness and has a greater torque to failure than the intact capsule.

Influence of patient-, design-, and surgery-related factors on rate of dislocation after primary cementless total hip arthroplasty

We performed clinical, radiographic, and computed tomography examinations on a consecutive series of 1268 patients (1648 hips) to determine the prevalence of and factors contributing to dislocation after using a primary cementless total hip system. The prevalence of posterior dislocation was 3.6% (60 hips). Significant risk factors (Fisher exact test or chi(2) test, P < .05) were female sex, advanced age, high American Society of Anesthesiologists score (3 or 4), fracture of the femoral neck, nonrepair of the posterior soft-tissue sleeve, low or high cup anteversion, low or high stem anteversion, and low height of hip rotation center.

MRI shows biologic restoration of posterior soft tissue repairs after THA

Although posterior capsule repair reduces the incidence of dislocation after THA, radiographic imaging studies suggest a high failure rate of the repair. Using MRI, we prospectively followed patients to evaluate the integrity of the posterior soft tissue repair after primary THA. Thirty-six patients (21 men, 15 women) underwent arthroplasty using a standard posterior approach. The posterior capsule and external rotators were repaired as separate layers using nonabsorbable sutures through two drill holes in the greater trochanter. Patients observed postoperative hip precautions for 6 weeks after surgery. All patients underwent initial MRI between postoperative Days 2 and 4. Thirty patients returned for followup MRI 3 months after surgery. At 3 months followup, the posterior capsule remained intact in 27 of 30 patients (90%) and the quadratus femoris repair remained intact in 29 of 30 patients (97%). Thirteen of 30 piriformis tendon repairs (43%) and 17 conjoined tendon repairs (57%) showed a gap between the hypointense tendon end and the greater trochanter greater than 25 mm. Our data show repaired posterior soft tissues provide a biologic scaffold allowing formation of a posterior pseudocapsule.

Capsular-enhanced repair of the short external rotators after total hip arthroplasty

Higher dislocation rates have been reported with the posterior approach to the hip. Empirical studies suggest that careful repair of the posterior structures significantly reduces this risk. However, studies examining the integrity of repair using plain radiographs and metallic markers have reported high failure rates. To explain this discrepancy, we performed a study using radiostereometric analysis to assess the repair. Ten patients were recruited. Markers were placed into the capsule and bone. The capsule and conjoined short external rotators were repaired through drill holes in bone. At 3 months, stress radiostereometric analysis radiographs were taken in internal and external rotation. Eight of 10 patients had a mean of 3.51-mm difference in separation, suggesting that the repair was intact. We recommend careful repair of posterior structures when using the posterior approach to reduce the risk of dislocation.

Role of capsular repair on dislocation in revision total hip arthroplasty

Dislocation remains one of the most common complications after revision total hip arthroplasty (THA). In contrast to primary THA the posterior capsule has been routinely excised to provide better visualization, but its role in preventing dislocation has been overlooked. We reviewed 69 patients (79 hips) patients who had revision THA with a posterolateral approach to determine if closing the posterior capsule resulted in a fewer dislocations. We followed the patients for a minimum of 24 months (mean 57 months, range, 24-120 months). Two (2.5%) hips dislocated. Both dislocated anteriorly in the immediate postoperative period. One dislocation was from implant malposition and the other occurred in a high risk patient. There were no posterior dislocations and no patients reported any hip subluxation. The historically high dislocation rates with the posterolateral approach can be reduced by carefully balancing soft tissues, ensuring correct implant alignment, meticulously closing the posterior capsule, and reattaching the external rotators.

Anterior capsular repair in total hip arthroplasty performed for late-presenting displaced femoral neck fractures

Dislocation after total hip arthroplasty performed for femoral neck fractures occurs frequently due to the significantly higher range of movement of the postoperative hip joint. Proper wound closure can prevent the loss of structural support provided by the capsule and myofascial structures, and is essential for postoperative hip stability. On 32 consecutive patients (four men, 28 women; mean age 64 years, range 48-83 years) with unilateral late-presenting displaced femoral neck fractures, a careful anterior capsule repair technique during total hip arthroplasty was performed by a single surgeon between 1997 and 2000. At one-year follow-up, no dislocation had occurred in any patient. Intraoperative protection and careful anatomic reattachment of the hip joint capsule may increase the stability of the hip joint after total hip arthroplasty and lead to a lower incidence of dislocation.

Does surgical approach affect total hip arthroplasty dislocation rates?

Dislocation is a common complication of total hip arthroplasty, but exact effect of surgical approach on dislocation rates remains unclear. Because little randomized prospective data exist in this context, we performed a meta-analysis comparing dislocation rates using the posterior approach with and without soft tissue repair. A systematic literature review resulted in five studies which directly compared the posterior approach with and without soft tissue repair. The dislocation rates with and without repair were 0.49% and 4.46%, respectively. The relative risk for dislocation was determined using a fixed effects model with chi square test for interstudy heterogeneity. The posterior approach without soft tissue repair was found to have an 8.21 times greater relative risk of dislocation than with soft tissue repair (95% confidence interval, 4.05-16.67). A separate systematic review of 11 studies revealed comparable dislocation rates associated with the anterolateral, direct lateral, and posterior approaches with soft tissue repair (0.70%, 0.43%, and 1.01%, respectively). These data demonstrate that adequate soft tissue repair greatly reduces the relative risk of dislocation using the posterior approach, and that the dislocation rates for the three most prevalent approaches are similar. Further prospective randomized trials examining dislocation rates and other clinical parameters are needed.

Constrained liners in revision: total hip arthroplasty an overuse syndrome: in opposition

Use of constrained liners in revision total hip arthroplasty is frequently a necessary evil. Concomitant with the increasing complexity of the operative intervention is the deterioration of periarticular soft-tissue envelope integrity, causing increased risk of dislocation. Risk factors can be categorized as impingement independent or impingement related. Impingement-independent risk factors include those related to compromised soft-tissue tension, patient-specific issues, and surgical approach. Impingement-related risk factors include head-to-neck size and geometry, acetabular liner geometry, and surgical technique. Indications for constraint include recurrent hip instability after arthroplasty, intraoperative multidirectional hip instability, neuromuscular diseases that impair hip dynamics, neurologic diseases that impair the patient's ability to restrict activities, and proximal muscle weakness with or without deficiency of the protective muscular. Newer designs featuring large heads, improved range of motion, and reduced impingement hold the promise of improved results.

Dislocation of bipolar hemiarthroplasty: rate, contributing factors, and outcome

Dislocation of bipolar hemiarthroplasty of the hip is a rare complication. The objectives of our study were to assess the incidence, contributing factors, and outcomes of bipolar prosthesis dislocation. From 1974 to 2001, 1812 primary bipolar hemiarthroplasties were done at our institution. Seventy-four percent were done in patients with fractures of the femoral neck. An anterolateral surgical approach was used in 79% of hips, a posterolateral approach was used in 14% of hips, and a transtrochanteric approach was used in 7% of hips. Thirty-two hips dislocated. The cumulative probabilities of dislocation at 1 year, 5 years, 10 years, and 20 years were 1.1% (95% CI range, 0.6%-1.6%), 1.5% (95% CI range, 0.9%-2.1%), 2.1% (95% CI range, 1.2%-3.1%), and 5% (95% CI range, 1.9%-9.6%), respectively. There was no significant association of dislocation with the surgical approach or with the primary operative diagnosis. More than (1/2) of the dislocations occurred within 6 months postoperative. Late dislocations occurred most commonly in patients with Bateman prostheses and osteonecrosis and were associated with inner bearing dissociation. Closed reduction was successful in preventing additional surgery in only 30% of patients. The surgeon must be aware that closed reduction may be unsuccessful, and open reduction with replacement of components may be necessary.

LEVEL OF EVIDENCE

Therapeutic study, Level IV (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Metal-on-metal total hip arthroplasty with large heads may prevent early dislocation

Postoperative dislocation is one of the major causes of morbidity and failure of total hip arthroplasty. We reviewed 327 patients (377 hips) retrospectively with varying diagnoses and indications but all of whom received large-diameter metal-on-metal prostheses. Two surgical approaches were used: the anterolateral abductor splitting (342 procedures) and a mini-incision posterior approach (35 procedures). Average age at time of surgery was 55.9 years and average followup was 4.0 months. There were 346 (91.8%) primary procedures, 15 (4.0%) conversion procedures, and 16 (4.2%) revisions or reimplantations. The most common preoperative diagnoses included osteoarthritis (250 hips; 66.3%) and avascular necrosis (46 hips; 12.2%). There were 62 (16.4%) patients with high-risk diagnoses for dislocation. The status in terms of postoperative dislocation was known for all patients. During the short followup period, there were no dislocations. Use of large-diameter femoral heads and metal-on-metal articulations decreases the risk of dislocations, making their use a viable choice for primary and revision procedures.

LEVEL OF EVIDENCE

Therapeutic study, Level IV-1 (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Isolated acetabular revision through the posterior approach: short-term results after revision of a recalled acetabular component

Isolated acetabular revision is commonly associated with high rates of postoperative dislocation. We hypothesize that the dislocation rate in a series of isolated acetabular revisions for loosening of recalled acetabular components is low when strict intraoperative stability testing is coupled with re-repair of the piriformis tendon. Twenty-six isolated revisions of aseptic, loose recalled acetabular components were performed through the posterior approach by a single surgeon. All piriformis tendon and posterior capsular repairs from the index operation were considered intact at the time of revision. The piriformis tendon was re-repaired in each revision case. The average revision acetabular component was 3 mm larger than the index component. In this select group of isolated acetabular revisions, strict intraoperative stability testing and re-repair of the piriformis tendon yielded zero dislocations.

Anterolateral mini-incision hip replacement surgery: a modified Watson-Jones approach

Mini-incision total hip replacement seeks to eliminate some complications of traditional extensile exposure and also attempts to facilitate more rapid rehabilitation of patients after surgery. Different surgical approaches historically have been used to do hip replacement surgery. Anterior or anterolateral approaches have often been selected to decrease the risk of posterior dislocation. Traditional anterolateral approaches have divided the anterior portion of the gluteus medius and minimus and potentially jeopardized the superior gluteal nerve. These disadvantages have been associated with abductor weakness, prolonged limp and decreased patient satisfaction. To overcome these problems, a mini-incision approach was developed using the intermuscular plane between the gluteus medius and the tensor fascia lata. This intermuscular interval through a small incision provides good exposure for total hip replacement and preserves muscle integrity so that rehabilitation can be rapid and the posterior capsule remains intact so that posterior dislocation is less of an issue. The surgical technique for this new innovative approach is described in this article.

Mini-incision anterior approach does not increase dislocation rate: a study of 1037 total hip replacements

Correct positioning of the prosthetic components in total hip replacements is important to prevent dislocations. Correct positioning is made easier by extensive approaches, but it also is possible using the mini-incision approach. The mini-incision used to facilitate early rehabilitation should not produce a higher dislocation rate than that of the more conventional approaches. The anterior surgical approach we describe allows for good exposure, despite the reduced size of the skin incision. Its length is 5-10 cm and usually 6-8 cm for patients with normal corpulence. Our mini-incision anterior approach using intermuscular planes allows a surgical approach to the hip and implantation of a total prosthesis with no muscle, tendon, or trochanteric section, even partially. This is not possible with any other surgical approach. A series of 1037 primary total hip replacements done between June 1993 and June 2000 was studied retrospectively. The dislocation rate was 0.96% (10 of 1037 hips). The mini-incision approach allows for adequate positioning of the two prosthetic components. Preserving the muscular potential also may contribute to dynamic stabilization of the hip.

Posterior capsular repair following total hip arthroplasty: a modified technique

Various techniques of posterior capsular repair following THA have been reported and studies have demonstrated the merits of posterior capsular repair with respect to decreasing the incidence of dislocation. Our modified technique using three sutures offers excellent fixation of the hip capsule on the greater trochanter. The small drill holes needed for the #2 Fiberwire minimize the risk of a greater trochanteric fracture through the drill holes and osteoporotic bone. To date, we have not experienced any complications or reaction to this material. The importance of a posterior capsule repair has been well documented in the literature. A rigid capsular repair can prevent excess internal rotation and therefore minimize the incidence of postoperative dislocation following THA.

Failure of capsular enhanced short external rotator repair after total hip replacement

The failure rate of repaired short external rotator muscles was determined in 20 total hip replacements done in 19 patients. The piriformis, both obturator and gemellus muscles, and the capsule were released close to the femur in a single flap leaving the tendon-capsule junction intact. After implantation of the prosthetic components, the flap was transosseously reattached with three grasping stitches, each encompassing the entire tendon-capsule junction. Radiopaque markers were attached to each side of the suture. The distance between markers was measured intraoperatively and then determined on radiographs 1 day and 3 months postoperatively; 25 mm or more and at least double the distance measured intraoperatively indicated failure. In 15 of the 20 hips the repair failed; in three hips the repaired flap was pulled out within the first day, and in 12, within 3 months. Capsular enhanced repairs of the short extensor rotator muscles, using the technique described, largely are unable to withstand forces that occur at the site of repair during the healing process. The quality of other repair techniques should be determined to identify superior techniques.