Total knee arthroplasty in patients with poliomyelitis

Survivorship of total knee arthroplasty in poliomyelitis patients: long-term results from the R.I.P.O. registry and single-institution retrospective study

INTRODUCTION

The survival of total knee arthroplasty (TKA) in patients with poliomyelitis remains a debated topic due to the high recurrence of postoperative genu recurvatum. This study aims to report the long-term survival of TKA in patients with poliomyelitis, using data from the Italian Register of Prosthetic Implantology.

MATERIALS AND METHODS

A registry-based population study was conducted, utilizing data from the Emilia Romagna orthopedic arthroplasty implants registry (RIPO - Registro Implantologia Protesica Ortopedica). The cohort consisted of 71 patients with poliomyelitis-related arthritis who underwent TKA. The study assessed and analyzed demographic data, implant type, fixation method, insert type, and level of constraint. Additionally, variations in preoperative and postoperative both clinical and functional Knee Society Scores (KSS) were collected.

RESULTS

Eight implants required revision surgery (16%), and three patients died (6.1%), resulting in a 10-year survival rate of 86.6% and a 15-year survival rate of 53.9%. Aseptic loosening was the primary cause of revision, accounting for 37.5% of failures, followed by insert wear (25%). No statistically significant correlation was found between the level of constraint and implant survival (p=0.0887, log-rank). Both the clinical and functional KSS improved postoperatively.

CONCLUSION

TKA is a viable alternative to knee arthrodesis and, in properly selected patients, might represent the first-choice treatment for articular degeneration due to its high survivorship. Despite the complexity of these cases, TKA can effectively alleviate articular pain, instability, and angular deviation, thereby preserving knee functionality.

High Recurrence Rates of Hyperextension After Total Knee Arthroplasty in Asian Patients With Preoperative Knee Hyperextension: A Prospective Observational Study

INTRODUCTION

Genu recurvatum is a well-known problem in total knee arthroplasty (TKA) in patients with and without neuromuscular disorders. Hyperextension of the knee joint does not reoccur significantly following adequate correction during TKA is the generally accepted notion. The literature regarding the reoccurrence of genu recurvatum in patients after TKA with preoperative genu recurvatum is scarce. The current study is an intermediate-range follow-up study to assess the pre- and postoperative sagittal plane profiles of Asian patients with genu recurvatum who underwent TKA. Changes in the sagittal profile in the immediate postoperative period were compared with the sagittal plane profile during the follow-up to the time of the final follow-up.

MATERIALS AND METHODS

This study was a prospective observational study of 21 patients (35 knees) with preoperative hyperextension of the affected knee who underwent total knee arthroplasty between July 2014 and September 2018, in our centre. The inclusion criteria were patients with primary osteoarthritis of the knee with recurvatum deformity ≥5° as measured preoperatively on a standing lateral radiograph. The exclusion criteria were neuropathic joints, post-traumatic arthritis, inflammatory arthritis, arthritis-associated neuromuscular disorders and revision procedures. The preoperative patients were divided into two groups: those with hyperextension of ≤10° and those with hyperextension of >10°. Radiographic measurements were done using the DICOM software (Kriens, Switzerland). The mean follow-up was 4.7 years (range: 3.6 to 7.6 years), and the minimum follow-up period was 3.6 years. No patients were lost to follow-up. All patients were evaluated clinically pre- and postoperatively using the Knee Society score. The knee range of movement and the coronal and sagittal profiles were recorded using standing radiographs. Statistical evaluation was done using the Chi-square test and the Wilcoxon signed-rank tests (SPSS version 17, Chicago, IL SPSS Inc, 2008).

RESULTS

Twenty-one patients (35 knees) with preoperative knee hyperextension underwent total knee arthroplasty with the mean age of patients being 59.38 years and the mean BMI of 32.28. The mean preoperative hyperextension was -10.1° (range: -5° to -26°). Early postoperative sagittal alignment (mean) was +4.5° (3° to 10°), and the mean sagittal alignment at final follow-up was -10.9° (-5° to -15°) (positive values indicate residual knee flexion, and negative values indicate hyperextension). There was no significant difference in the preoperative sagittal profiles of patients with BMI <30 and ≥30 (p=0.43). There was no statistically significant difference (p=0.19) between those with hyperextension of ≤10° and those with hyperextension of >10°.

CONCLUSION

 Till now, none of the patients have complained of symptoms related to hyperextension, although the rate of recurrence of hyperextension is high. Long-term follow-up is essential in patients with recurvatum deformity who have undergone TKA since delayed recurrence of hyperextension is possible despite adequate intraoperative correction of the deformity. Accurate preoperative prediction about the magnitude of postoperative deformity is not feasible. It is essential to counsel patients preoperatively that hyperextension may recur even after exercising sufficient care in the operative procedure to minimize its occurrence.

Alignment and Fixation in Revision Total Knee Arthroplasty With Press-Fit, Offset, Diaphyseal-Engaging Stem Extensions, and Eccentric Reaming Technique

BACKGROUND

A revision total knee arthroplasty must control limb alignment, often to address the cause of failure. Press-fit stems that engage the diaphysis with cement restricted to the metaphysis constitute one fixation technique. These long stems restrict coronal alignment of the prosthesis and as a result reduce the likelihood of extreme malposition. For the same reasons, long stems can make it difficult to manipulate alignment and achieve a specific coronal alignment angle. Nevertheless, femoral stems with a tight diaphyseal fit may still occupy a small range of varus-valgus positions due to the conical distal femoral metaphysis. Pulling the reamer toward the lateral endosteum increases femoral component coronal alignment toward a valgus direction and pushing the reamer medially increases alignment in a more varus direction. A straight stem, in combination with a medially directed reaming, would result in a femoral component that overhangs medially, but an offset stem can recenter the femoral component and maintain the desired alignment. We hypothesized that diaphyseal fit plus this reaming technique can control limb coronal alignment and provide fixation.

METHODS

This was a retrospective clinical and long-leg radiographic study of consecutive revision total knee arthroplasties with minimum 2-year follow-up. Outcomes were correlated with New Zealand Joint Registry data to identify rerevisions of 111 consecutive revision knee arthroplasties, 92 after exclusions, at a minimum 2-year (range, 2 to 10) follow-up.

RESULTS

Mean femoral and tibial canal fill exceeded 91% on antero-posterior and lateral radiographs. The mean hip-knee-ankle angle was 179.6o (174.9-184.0) with 80% within ± 3o of neutral. The hip-ankle axis crossed the central Kennedy zone in 76.5% of cases and the other 24.6% crossed the inner medial and inner lateral zones. Tibial components: 99.0% ± 3o. Femoral components: 89.5% within ± 3o. There were 5 knees that failed due to infection, 3 from femoral loosening, and 1 due to recurvatum instability from polio.

CONCLUSIONS

This study describes a surgical plan and technique for achieving target coronal alignment with press-fit diaphyseal fixation. It is the only series of revision knee arthroplasties with diaphyseal press-fit stems to report canal fill in 2 planes and coronal alignment on full-length radiographs.

Bilateral Total Knee Replacement in a Patient With Poliomyelitis: A Case Report From Eastern Morocco

Total knee replacement in limbs affected by poliomyelitis can be complicated by anatomical features, narrowing of the intramedullary canal, quadriceps muscle weakness, flexion contractures, and ligament laxity. Total knee arthroplasty (TKA) leads to good results in returning to daily activities and overall functional improvement of these polio patients by restoring near-normal joint mobility, pain relief despite impaired quadriceps strength, and bone and soft tissue defects. Our case report is about a patient with sequelae of bilateral poliomyelitis of the limb benefiting from a hinge-type total knee prosthesis. The rotating hinge total knee prosthesis has certainly been a revolution in the surgical treatment of patients with poliomyelitis, bringing considerable functional improvement. Nevertheless, total knee replacement on poliomyelitis limbs is still a therapeutic challenge, even for the most experienced hands.

Total knee replacements using rotating hinge implants in polio patients: clinical and functional outcomes

Little evidences are available in the literature concerning the outcomes of total knee replacement (TKR) in poliomyelitis patients with severe knee deformities or degeneration. Encouraging results have been reported concerning the use of constrained implants, i.e., rotating hinge knee prosthesis (RHK), compared to less constrained ones. The purpose of this paper is to report our experience with rotating hinge total knee replacement, using only RHK prosthesis, to determine functional results, complications, and survival of TKR in poliomyelitis patients. We performed a retrospective chart review of 14 patients with a history of knee osteoarthritis following poliomyelitis that underwent primary TKR, for a total of 15 surgical procedure (one bilateral case). Preoperative and postoperative clinical measurements have been conducted for all patients using the Knee Society Score (KSS). Hip-knee angle, recurvatum knee angle, and Insall-Salvati index were evaluated with full weight-bearing panoramic view X-ray preoperatively and postoperatively. The 2-year postoperative clinical KSS significantly improved from the preoperative scores. The average clinical KSS improved from 32,9 (range 3-48) preoperatively to 77,4 (range 60-88) postoperatively (P value < 0.005). The average functional KSS improved from 32,5 (range 10-60) preoperatively to 59,4 (range 30-95) postoperatively (P value < 0.005). TKR is a successful treatment in improving knee function and patient's quality of life. Using constrained implants, especially rotating hinge implants in polio patients with a quadriceps muscle weakness, could be a good alternative to maintain a physiological kinematics and reducing the revision rate due to knee instability.

Total knee replacement in a polio patient with prior extension osteotomy: a case report

Poliomyelitis is an infectious disease characterized by a loss of motor neurons. Affected individuals usually suffer from many abnormalities predisposing them to degenerative joint disease. We report a case of a young male, with a history of poliomyelitis, distal femoral extension osteotomy and previous tendon transfer, suffering from severe knee pain. The patient underwent total knee arthroplasty with posterior stabilized Triathlon® for the femoral side reconstruction and Total-stabilizer Triathlon® for the tibia with short stem. At 2-year follow-up, his range-of-motion had improved, and he could walk without pain. This case report emphasizes the value of careful preoperative planning for a complex case with suitable implants and expecting realistic outcomes.

Posterior-Stabilized TKA in Patients With Severe Genu Recurvatum Achieves Good Clinical and Radiological Results at 5-year Minimum Follow-Up: A Case-Controlled Study

BACKGROUND

Genu recurvatum is a rare knee deformity. Total knee arthroplasty (TKA) in severe preoperative recurvatum requires surgical adjustments. Few studies have assessed the clinical and radiological results of TKA in recurvatum. The aim was to compare the clinical and radiological outcomes, complications, and revision rates after posterior-stabilized TKA in severe recurvatum with those without recurvatum.

METHODS

Between 1987 and 2015, 32 primary posterior-stabilized TKA were performed with a preoperative genu recurvatum greater than 10° and minimum follow-up of 60 months. In severe genu recurvatum, the extension gap needs to be decreased compared with flexion gap. To achieve this, the distal femoral cut is distalized, whereas the posterior femoral and tibial cuts are performed as usual. They were compared with 64 matched posterior-stabilized TKAs without recurvatum. The demographic data were similar between groups. The clinical and radiological outcomes, complications, and revision rates were assessed at the last follow-up.

RESULTS

At a mean follow-up of 7.4 years ± 1.9, there was no significant difference in International Knee Score functional score (77.5 vs. 73.4; P = .50) and knee score (86.6 vs. 89.5; P = .37) between the recurvatum group and the control group, respectively. 6 patients had a postoperative recurvatum equal or superior to 10° in the recurvatum group (18.8%). There was no difference between both groups in radiological outcomes, complication, or revision rates. No instability was found in the recurvatum group.

CONCLUSION

Posterior-stabilized TKA with controlled distalization of the femoral component in the setting of severe preoperative genu recurvatum achieves good clinical and radiological outcomes at a minimum follow-up of 5 years and similar to TKA without preoperative recurvatum.

LEVEL OF EVIDENCE

III.

Posterior tibial slope is a modifiable predictor of relatively large extension gaps in total knee arthroplasty for degenerative osteoarthritis

BACKGROUND

During total knee arthroplasty (TKA) for osteoarthritis, the sagittal gap imbalance (SGI) with a relatively large extension gap is an important surgical challenge. We determined the predictors of SGI with a relatively large extension gap and evaluated the surgical outcomes of knees with SGI.

METHODS

551 consecutive cases of primary TKA for osteoarthritis were retrospectively reviewed. The cohort was divided into two groups according to the SGI and statistically matched according to baseline characteristics via the inverse probability of treatment weighting method. Multiple linear and logistic regression analyses were performed to determine the predictors of sagittal gap difference (SGD) and SGI. Intergroup differences in clinical and radiological outcomes were analyzed.

RESULTS

Of all the knees included, 8.5% (n = 45) presented with SGI with a relatively large extension gap and required femoral sagittal balancing to manage SGI. The hyperextension angle (HA), preoperative joint line convergence angle (JLCA), and the change in posterior tibial slope (PTS) significantly correlated to SGD and predicted SGI with a relatively large extension gap. SGI group showed significant changes in femoral posterior condylar offset and joint line height compared to those without SGI (1.48 vs -0.45, 1.37 vs -0.51, respectively). Postoperative ROM and knee society knee scores were lower in SGI group.

CONCLUSION

Knees requiring sagittal balancing to manage SGI with a relatively large extension gap is not uncommon in TKA for osteoarthritic knees. The change in PTS is an independent and modifiable predictor of SGI.

Balance and constraint in revision TKR: A classification for instability management

Instability is an increasingly common cause and symptom of failure of Total Knee Arthroplasty (TKA). Patients seek 'Functional Stability', which is the sum of both a balanced joint and, if necessary, mechanical constraint. The objective of this paper is to classify the different types of TKA instability and their causes. Based on this classification, the authors give methodical recommendations for instability management.

Instability classification

Instability in revision TKA can be classified into 3 types based on the management of bone loss and ligamentous deficiency which directs the level of constraint required to achieve functional stability.

Type 1

Bone deficiency: Revision with restoration of joint line and rebuilding the bony anatomy results in a balanced joint. No increased constraint is needed.

Type 2

Ligament and soft tissue deficiency: Requires increased constraint to overcome instability.

Type 3

Composite (Total) deficiency: (combined Type 1 and 2).The multiple causes of instability are outlined for each Instability type along with an algorithm for restoring the joint line and adding titrated constraint to restore functional stability.

Difficult primary total knee arthroplasty requiring a varus-valgus constrained implant is at higher risk of periprosthetic infection

PURPOSE

The goal of this study was to compare the risk of periprosthetic infection of a consecutive cohort of primary varus-valgus constrained (VVC) total knee arthroplasties (TKAs), with a matched 1:1 cohort of primary posterior-stabilized (PS) TKAs.

METHODS

74 primary VVC TKAs performed in 66 patients were identified and matched 1:1 with a cohort of 74 primary PS TKAs performed in 73 patients. At last follow up, patients were clinically evaluated using the Knee Society Score (KSS). Kaplan-Meier survival curves were generated to analyze survivorship using as endpoints revision for any reason, revision for periprosthetic infection and revision for mechanical failure after excluding periprosthetic infection. A multivariate logistic regression analysis was constructed to determine whether revision surgery for periprosthetic infection was influenced by patients' gender, age, surgical time and reasons for TKA (primary vs secondary osteoarthritis).

RESULTS

Demographic data were not significantly different between the two groups as regard patients' age, gender, body mass index, Charlson Comorbidity Index, reasons for replacement, and length of follow-up. Surgical time was greater in the VVC group (95.7 ± 22.5 min vs 88.6 ± 17.1 min, respectively, p = 0.032). Postoperative KSS, range of motion and radiographic data did not differ significantly between the two groups. Overall revision rate and revision rate for mechanical failure after 5 years of follow-up was not statistically different between the two groups. Considering only the revision rate due to periprosthetic infection, the risk was higher in patients with primary VVC implants (p = 0.013). The surgical time was the only factor that significantly affected the risk of revision for periprosthetic infection (OR 1.0636, CI 95% 1.0209-1.1081, p = 0.0032), whereas patients' gender, age and reason for TKA had no influence.

CONCLUSIONS

Patients and surgeons should be aware of the higher risk of periprosthetic knee infection using a VVC prosthesis. However, the present study supports the use of VVC implants in cases of difficult knee replacements, since comparable clinical outcomes and overall revision rate was found after at least 5 years of follow up.

LEVEL OF EVIDENCE

Retrospective cohort study, Level III.

A Systematic Review of Total Knee Arthroplasty in Neurologic Conditions: Survivorship, Complications, and Surgical Considerations

BACKGROUND

Patients with neurologic disorders present a unique set of challenges for knee surgeons because of contractures, muscle weakness, spasticity, and ligament instability. The primary purpose of this review was to report the outcomes of total knee arthroplasty (TKA) in these patients, including survivorship, complications, and surgical considerations.

METHODS

We performed a systematic review of articles using PubMed, Cochrane Central, EMBASE, and Google Scholar. All studies reporting outcomes of TKA in patients with Parkinson disease, multiple sclerosis, poliomyelitis, Charcot joint, spina bifida, stroke, and cerebral palsy were included.

RESULTS

In total 38 studies were included: 22 studies (461 patients) reported patient-reported outcome measures and 24 studies (510 patients) reported survivorship. All 38 studies reported complication rates. TKA resulted in an improvement in functional outcome in all series. Complication rate was higher in patients with neurologic conditions. Of studies reporting survivorship, mean follow-up ranged from 1 to 12 years with survivorship from 66% to 100%. All levels of implant constraint were reported without consensus. Limited rehabilitative data exist.

CONCLUSION

TKA in patients with neurologic disorders improves symptoms and function but carries significant risk. This review helps surgeons preoperatively counsel their patients in an informed manner. Careful planning, perioperative care, and appropriate implant selection may mitigate risk of complication.

Inhospital Complications of Patients With Neuromuscular Disorders Undergoing Total Joint Arthroplasty

INTRODUCTION

Orthopaedic surgeons are wary of patients with neuromuscular (NM) diseases as a result of perceived poor outcomes and lack of data regarding complication risks. We determined the prevalence of patients with NM disease undergoing total joint arthroplasty (TJA) and characterized its relationship with in-hospital complications, prolonged length of stay, and total charges.

METHODS

Data from the Nationwide Inpatient Sample from 2005 to 2014 was used for this retrospective cohort study to identify 8,028,435 discharges with total joint arthroplasty. International Classification of Diseases, Ninth Revision, Clinical Modification codes were used to identify 91,420 patients who had discharge diagnoses for any of the NM disorders of interest: Parkinson disease, multiple sclerosis, cerebral palsy, cerebrovascular disease resulting in lower extremity paralysis, myotonic dystrophy, myasthenia gravis, myositis (dermatomyositis, polymyositis, and inclusion-body myositis), spinal muscular atrophy type III, poliomyelitis, spinal cord injury, and amyotrophic lateral sclerosis. Logistic regression was used to estimate the association between NM disease and perioperative outcomes, including inpatient adverse events, length of stay, mortality, and hospital charges adjusted for demographic, hospital, and clinical characteristics.

RESULTS

NM patients undergoing TJA had increased odds of total surgical complications (odds ratio [OR] = 1.21; 95% confidence interval [CI], 1.17 to 1.25; P < 0.0001), medical complications (OR = 1.41; 95% CI, 1.36 to 1.46; P < 0.0001), and overall complications (OR = 1.32; 95% CI, 1.28 to 1.36; P < 0.0001) compared with non-NM patients. Specifically, NM patients had increased odds of prosthetic complications (OR = 1.09; 95% CI, 0.84 to 1.42; P = 0.003), wound dehiscence (OR = 5.00; 95% CI, 1.57 to 15.94; P = 0.0002), acute postoperative anemia (OR = 1.20; 95% CI, 1.16 to 1.24; P < 0.0001), altered mental status (OR = 2.59; 95% CI, 2.24 to 2.99; P < 0.0001), urinary tract infection (OR = 1.45; 95% CI, 1.34 to 1.56; P < 0.0001), and deep vein thrombosis (OR = 1.27; 95% CI, 1.02 to 1.58; P = 0.021). No difference of in-hospital mortality was observed (P = 0.155).

DISCUSSION

Because more patients with NM disease become candidates of TJA, a team of neurologists, anesthesiologists, therapists, and orthopaedic surgeon is required to anticipate, prevent, and manage potential complications identified in this study.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Outcome of total knee arthroplasty in patients with poliomyelitis: A systematic review

Total knee arthroplasty (TKA) in patients affected by poliomyelitis is technically challenging owing to abnormal anatomical features including articular and metaphyseal angular deformities, external rotation of the tibia, excessive valgus alignment, bone loss, narrowness of the femoral and tibial canals, impaired quadriceps strength, flexion contractures, genu recurvatum and ligamentous laxity. Little information is available regarding the results and complications of TKA in this challenging group of patients.

We carried out a systematic review of the literature to determine the functional outcome, complications and revision rates of TKA in patients with poliomyelitis-affected knees. Six studies including 82 knees met the inclusion criteria and were reviewed. The mean patient age was 63 years (45 to 85) and follow-up was 5.5 years (0.5 to 13).

All studies reported significant improvement in knee function following TKA. There were six failures requiring revision surgery in 82 cases (7%) occurring at a mean of 6.2 years (0.4 to 12). The reasons for revision surgery were aseptic loosening (17%, n=1), infection (33%, n=2), periprosthetic fracture (17%, n=1) and instability (33%, n=2). Thirty-six knees had a degree of recurvatum pre-operatively (44%), which was in the range of 5° to 30°. Ten of these knees (28%) developed recurrent recurvatum post-operatively.

The findings support the use of TKA in patients with poliomyelitis-affected knees. The post-operative functional outcome is similar to other patients; however, the revision rate is higher. Quadriceps muscle power appears to be an important prognostic factor for functional outcome and the use of constrained implant designs is recommended in the presence of less than antigravity quadriceps strength.

Cite this article: EFORT Open Rev 2018;3:358-362. DOI: 10.1302/2058-5241.3.170028

Outcomes of total knee arthroplasty in degenerative osteoarthritic knee with genu recurvatum

BACKGROUND

This study aimed to assess the incidence of genu recurvatum without neuromuscular disorders in knees that underwent navigation-assisted total knee arthroplasty (TKA), to evaluate short-term radiologic and clinical results of navigation-assisted TKA in genu recurvatum, and to evaluate differences in results according to the degree of pre-operative hyperextension and type of implant and insert.

METHODS

This study retrospectively reviewed 510 knees that underwent navigation-assisted TKA from January 2005 to December 2011. The incidence of knees that showed hyperextension of ≥5° (genu recurvatum) on navigation, and the accompanying alignment were evaluated. It assessed radiologic, intraoperative, and clinical results in recurvatum and control groups by using propensity score matching.

RESULTS

A total of 465 knees underwent navigation-assisted TKA for degenerative osteoarthritis. Genu recurvatum was observed in 55 knees (11.8%). Of these, 41 knees (74.5%) had degree of hyperextension between five degrees and 10°, and 47 (85.4%) had varus alignment. The thickness of the resected distal femur in the recurvatum group (7.6±1.6mm) was less than that in the control group (8.4±1.4mm, P=0.001). The thickness of the insert in the recurvatum group (12.5±2.3mm) was greater than in the control group (10.8±1.5mm, P<0.001). The sagittal alignment at the final follow-up was 1.3±3.4° in the control group and -0.1±0.7° in the recurvatum group (P=0.003). Subgroup analyses in the recurvatum group showed no significant difference in sagittal alignment and patient-related outcomes by degree of pre-operative hyperextension and implant/insert type (P>0.05 for all parameters).

CONCLUSIONS

Genu recurvatum was not uncommon among patients undergoing primary TKA. This review obtained satisfactory short-term clinical and radiologic results, with a smaller distal femoral resection and thicker insert.

Outcomes of Total Knee Arthroplasty in Patients With Poliomyelitis

BACKGROUND

We report our experience with outcomes of poliomyelitis in the Asian population.

METHODS

Sixteen total knee replacements in 14 patients with polio-affected knees were followed up for at least 18 months. Follow-up assessment included scoring with the American Knee Society Score (AKSS), Oxford knee score, and Short Form 36 Health Survey scores.

RESULTS

The mean AKSS improved from 25.59 preoperatively to 82.94 at 24 months, with greater improvement in the knee score. The mean Oxford knee score improved from 40.82 preoperatively to 20.53 at 24 months. The mean AKSS pain score rose from 2.35 to 47.66 at 24 months. The Short Form 36 Health Survey physical functioning and bodily pain scores improved for all patients.

CONCLUSION

Primary total knee arthroplasty of poliomyelitis-affected limbs shows good outcomes, improving quality of life, and decreasing pain.

Shoulder arthroplasty for sequelae of poliomyelitis

BACKGROUND

Polio infection can often lead to orthopedic complications such as arthritis, osteoporosis, muscle weakness, skeletal deformation, and chronic instability of the joints. The purpose of this study was to assess the outcomes and associated complications of arthroplasty in shoulders with sequelae of poliomyelitis.

METHODS

Seven patients (average age, 70 years) were treated between 1976 and 2013 with shoulder arthroplasty for the sequelae of polio. One patient underwent reverse shoulder arthroplasty, 2 had a hemiarthroplasty, and 4 had total shoulder arthroplasty. Average follow-up was 87 months. Outcome measures included pain, range of motion, and postoperative modified Neer ratings.

RESULTS

Overall pain scores improved from 5 to 1.6 points (on a 5-point scale) after shoulder arthroplasty. Six shoulders had no or mild pain at latest follow-up, and 6 shoulders rated the result as much better or better. Mean shoulder elevation improved from 72° to 129°, and external rotation improved from 11° to 56°. Average strength in elevation decreased from 3.9 to 3.4 postoperatively, and external rotation strength decreased from 3.9 to 3.3. This, however, did not reach significance. Evidence of muscle imbalance with radiographic instability was found in 4 shoulders that demonstrated superior subluxation, anterior subluxation, or both. This remained asymptomatic. No shoulder required revision or reoperation.

CONCLUSIONS

Shoulder arthroplasty provides significant pain relief and improved motion in patients with sequelae of poliomyelitis. Muscle weakness may be responsible for postoperative instability, and careful selection of the patient with good upper extremity muscles must be made.

The difficult primary total knee arthroplasty: a review

Primary total knee arthroplasty (TKA) is a reliable procedure with reproducible long-term results. Nevertheless, there are conditions related to the type of patient or local conditions of the knee that can make it a difficult procedure. The most common scenarios that make it difficult are discussed in this review. These include patients with many previous operations and incisions, and those with severe coronal deformities, genu recurvatum, a stiff knee, extra-articular deformities and those who have previously undergone osteotomy around the knee and those with chronic dislocation of the patella. Each condition is analysed according to the characteristics of the patient, the pre-operative planning and the reported outcomes. When approaching the difficult primary TKA surgeons should use a systematic approach, which begins with the review of the existing literature for each specific clinical situation.

Custom rotating hinge total knee arthroplasty in patients with poliomyelitis affected limbs

PURPOSE

Total knee arthroplasty (TKA) in limbs affected by poliomyelitis is a technically challenging procedure. These patients often demonstrate acquired articular and metaphyseal angular deformities, bone loss, narrowness of the intramedullary canals, impaired quadriceps strength, flexion contractures and ligamentous laxity producing painful hyperextension. Thus, using condylar knee designs in these patients will likely result in early failure because of instability and abnormal load distribution. The aim of this study was to assess the outcomes associated with use of the customised (SMILES) rotating-hinge knee system at our institution for TKA in poliomyelitis-affected limbs.

METHODS

We retrospectively reviewed the outcome of 14 TKAs using the (SMILES) prosthesis in 13 patients with limbs affected by poliomyelitis. All patients had painful unstable knees with hyperextension. There were ten females and three males with a mean age of 66 years (range 51-84) at time of surgery. Patients were followed up clinically, radiologically and functionally with the Oxford knee score (OKS). Mean follow-up was 72 months (16-156).

RESULTS

There were no immediate or early complications. One patient fell and sustained a peri-prosthetic fracture at seven months requiring revision to a longer stem. Radiological evaluation showed satisfactory alignment with no signs of loosening in all cases. Mean OKS improved from 11.6 (4-18) to 31.5 (18-40) postoperatively (p < 0.001).

CONCLUSION

The rotating hinge (SMILES) prosthesis is effective at relieving pain and improving function in patients with poliomyelitis. The device compensates well for ligamentous insufficiency as well as for any associated bony deformity.

Bilateral custom-fit total knee arthroplasty in a patient with poliomyelitis

In limbs affected by poliomyelitis, total knee arthroplasty results in satisfactory pain relief. However, the risk of failure is high, especially if the preoperative quadriceps power is low. Therefore, treating osteoarthritis in the current patient represented a challenging procedure. A 66-year-old man presented with tricompartmental osteoarthritis of both knees, with valgus deformity of 14° on the left knee and 11° on the right knee. He walked with a bilateral knee recurvatum of 30° and a grade 1 quadriceps power. The authors treated both knees with cemented custom-fit hinged total knee arthroplasty with 30° of recurvatum in the tibial keel. Clinical scores showed good results 1 year postoperatively, especially on the subjective data of quality of life and function. At follow-up, radiographs showed good total knee arthroplasty positioning on the right side and a small mechanical loosening at the end of the tibial keel on the left side. Only 5 studies (Patterson and Insall; Moran; Giori and Lewallen; Jordan et al; and Tigani et al) have reported total knee arthroplasty results in patients with poliomyelitis. This study reports an original case of bilateral custom-fit hinged total knee arthroplasty in a patient with poliomyelitis. To the authors' knowledge, this is the first report of this type of procedure in the literature. The key point is the degree of recurvatum that is needed to allow walking, avoiding excessive constraints on the implants that can lead to early mechanical failure.

Custom rotating-hinge total knee replacement in patients with spina bifida and severe neuromuscular dysfunction

Spina bifida (SB) is a congenital disorder which may result in a number of musculoskeletal problems. Total knee replacement (TKR) in this patient group is technically demanding due to bone deformity, soft tissue contracture, muscle tone abnormality and ligament insufficiency. This is a retrospective review of three patients with SB and disabling knee arthritis who were managed with a custom rotating-hinge (RHK) total knee system. All patients reported an improvement in knee pain and stability at mean follow-up 47 months (43-53). Mean Oxford Knee score improved from 21 preoperatively to 32 at final follow-up. One patient required revision of tibial and patella components at 37 months for lateral patella instability and excessive wear. Custom RHK for patients with SB, severe neuromuscular dysfunction and bone deformity relieves pain, restores stability and improves early knee function; however there is a significant risk of extensor mechanism complications and functional outcome is worse than primary TKR in the general population.

Instability in primary total knee arthroplasty

Instability is one of the most common causes of failure of total knee arthroplasty (TKA). The presentation can vary from pain to frank dislocation with the etiologies just as varied. Instability after TKA can be classified by where the instability occurs in the knee's arc of motion as well as the chronicity of the problem. Acute instability is related to intraoperative injuries or excessive release of important coronal stabilizers such as the medial collateral ligament in extension or the posterolateral corner in flexion. Chronic instability in extension is often related to varus/valgus malalignment. Chronic instability in flexion can be related to an undersized femoral component, excessive tibial slope, or excessive elevation of the joint line affecting the isometry of the collateral ligaments in midflexion. Recurvatum instability is a rare complication that often coincides with extensor mechanism dysfunction or neuromuscular disorders. When addressing instability after TKA, it is critical to determine the root cause of the problem as well as evaluate for other causes of pain such as infection or aseptic loosening. When revision surgery is warranted, it should follow the basic principles of restoring a neutral mechanical alignment, setting the appropriate component rotation, balancing the flexion and extension spaces, and restoring the height of the native joint line.