The outcomes of total knee arthroplasty in morbidly obese patients: a systematic review of the literature.

INTRODUCTION: The increasing prevalence of obesity has led to an increase in total knee arthroplasties (TKAs) being undertaken in patients with a higher body mass index (BMI). TKA in morbidly obese patients can be technically challenging due to numerous anatomical factors and patient co-morbidities. The long-term outcomes in this patient group are unclear. This systematic review aims to compare the long-term revision rates, functional outcomes and complication rates of TKAs in morbidly obese versus non-obese patients. METHODS: A search of PubMed, EMBASE and PubMed Central was conducted to identify studies that reported revision rates in a cohort of morbidly obese patients (BMI ≥ 40 kg/m2) that underwent primary TKA, compared to non-obese patients (BMI ≤ 30 kg/m2). Secondary outcomes included Knee Society Objective Scores (KSOS), Knee Society Functional Scores (KSFS), and complication rates between the two groups. The difference in revision rates was assessed using the Chi-squared test. The Wilcoxon signed-rank test was used to compare pre-operative and post-operative functional scores for each group. KSOS and KSFS for morbidly obese and non-obese patients were compared using the Mann-Whitney test. Statistical significance was defined as p ≤ 0.05. RESULTS: Nine studies were included in this review. There were 624 TKAs in morbidly obese patients and 9,449 TKAs in non-obese patients, average BMI values were 45.0 kg/m2 (range 40-66 kg/m2) and 26.5 kg/m2 (range 11-30 kg/m2) respectively. The average follow-up time was 4.8 years (range 0.5-14.1) and 5.2 years (range 0.5-13.2) respectively, with a revision rate of 7% and 2% (p < 0.001) respectively. All functional scores improved after TKA (p < 0.001). Pre- and post-operative KSOS and KSFS were poorer in morbidly obese patients, however, mean improvement in KSOS was the same in both groups and comparable between groups for KSFS (p = 0.78). Overall complication rates,  including infection, were higher in morbidly obese patients. CONCLUSIONS: This review suggests an increased mid to long-term revision rate following primary TKA in morbidly obese patients, however, these patients have a functional recovery which is comparable to non-obese individuals. There is also an increased risk of perioperative complications, such as superficial wound infection. Morbidly obese patients should be fully informed of these issues prior to undergoing primary TKA.

Morbid Obesity Is a Significant Risk of Failure Following Revision Total Hip Arthroplasty.

BACKGROUND: Although it has been shown that morbidly obese patients experience good outcomes following primary total hip arthroplasty (THA), it is unclear whether this also applies to revision surgery. The purpose of this study was to examine the effect of a high body mass index (BMI) on the outcome of revision THA. METHODS: We identified 56 patients with a BMI >40 kg/m2 who had undergone revision THA between 1994 and 2009 at our hospital (group B). Mean age, BMI, and follow-up were 66.4 years, 45.7 kg/m2, and 11.7 years, respectively. This was matched with a second group of patients with a BMI between 30 and 40 kg/m2 according to age, gender, and date of index procedure (group A). Mean age, BMI, and follow-up were 66.6 years, 33.6 kg/m2, and 12 years, respectively. Outcome measures included the rate of subsequent revision, implant survival, and the Harris hip score (HHS). RESULTS: Patients with a BMI >40 kg/m2 had a significantly increased risk of revision surgery (27% vs 12%, P = .036). Cumulative implant survival was 85% (95% CI, 69-92) in group A and 69% (95% CI, 54-80) in group B at 15 years. HHS increased significantly following surgery in both groups (group A: 26.3-79.3) and (group B: 37.6-69.9; P < .001). However, HHS at last follow-up was significantly higher in group A (79.3 vs 69.9, P = .042). CONCLUSION: Morbid obesity appears to be associated with an increased risk of failure and lower functional scores following revision THA. Patients should be well informed of this before surgery.

Systematic review of the outcome of total hip arthroplasty in patients with sequelae of Legg-Calvé-Perthes disease.

BACKGROUND: Total hip arthroplasty (THA) in patients with sequelae of Legg-Calvé-Perthes disease (LCP) is technically demanding because of the disease related deformities occuring in the proximal femur and/or the multiplanar deformities secondary to corrective osteotomies in childhood. Little is known about the long-term outcome of the procedure in this challenging group of patients. METHODS: We carried out a systematic review of the literature to determine the functional outcome, complications and revision rate of THA in patients with sequelae of LCP disease. Six out of 148 potential studies involving 245 hips met the inclusion criteria. The mean age was 45.7 years (19-74) and follow-up was 8.4 years (2-21). RESULTS: There were 221 cementless THAs (90%), 22 hybrid THAs (9%) and 2 cemented THAs (1%). The femoral components used included 187 standard stems (76%), 43 modular stems (18%) and 15 custom-made stems (6%). The modular implants used were reamed S-Rom stems. All studies reported a significant improvement in hip function following THA. There were 16 revision THAs (7%) occurring at a mean of 7.5 years (0.4-10.3). Complications included intra-operative fracture (11%, n = 27), aseptic loosening (5%, n = 13), sciatic nerve palsy (3%, n = 7) and heterotopic ossification (2%, n = 4). All intra-operative fractures occurred when standard femoral stems were used. The average limb lengthening in the patients with a post-operative sciatic nerve injury was 1.9 cm. All patients with this complication had a history of previous hip surgery. CONCLUSIONS: THA in patients with LCP disease results in similar functional outcome compared to patients with primary osteoarthritis; however, the revision rate at mid-term follow-up is slightly increased. Reamed modular (S-Rom) and custom femoral implants appear to be associated with a decreased risk of intra-operative fracture. Care should be taken when addressing leg length discrepancy in this group of patients due to the increased risk of sciatic nerve palsy, especially in patients with prior surgical procedures.

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.

Custom cementless THA in patients with Legg-Calve-Perthes Disease.

Legg-Calve-Perthes disease is characterized by osteonecrosis of the femoral head during childhood. Outcomes of total hip arthroplasty (THA) for these patients are less satisfactory than for those with primary osteoarthritis, often complicated by young patient age, multi-planar deformities and previous childhood surgery. To our knowledge no one has reported the long-term outcomes of cementless custom-made THA in patients with Legg-Calve-Perthes disease. We reviewed 15 THAs with an average follow-up of ten years. Survivorship rates of the femoral and acetabular components were 100% and 79% respectively. Mean Harris Hip Scores improved from 41 preoperatively to 80 at final follow-up. With excellent functional outcome, custom-made cementless prostheses should be considered as a treatment option for osteoarthritis secondary to Legg-Calve-Perthes disease in the presence of abnormal proximal femoral and acetabular anatomy.

Proximal ulna endoprosthetic replacement for bone tumours in young patients.

PURPOSE: The optimal reconstructive method after resection of malignant bone tumours of the proximal ulna is unknown.We report the outcome of endoprosthetic replacement in a young patient population. METHODS: This was a retrospective review of four patients[three males and one female; mean age 17.5 (range 11­31)years] who underwent limb salvage with a proximal ulnar endoprosthetic replacement following excision of malignant bone tumour. Mean follow-up was 85 (range 14­194) months. RESULTS: All patients were alive at final follow-up and reported an improvement in pain. One patient required transhumeral amputation for intralesional excision complicating a local recurrence at one month. Two patients developed fixed flexion deformities of the elbow, one of whom required radial-head excision. Mean Musculoskeletal Tumour Society (MSTS)score and Toronto Extremity Salvage Score (TESS) were 27(range 25­28) and 81 (73­88), respectively. CONCLUSIONS: Custom-made proximal ulna endoprosthetic replacement following resection of malignant bone tumours in young patients provides a stable reconstruction option with satisfactory function and without apparent compromise in patient survival.

Metal-on-metal hip resurfacing arthroplasty provides excellent long-term survivorship and function in patients with a good-sized femoral head : results of a single, non-designer surgeon's cohort.

AIMS: To establish the survivorship, function, and metal ion levels in an unselected series of metal-on-metal hip resurfacing arthroplasties (HRAs) performed by a non-designer surgeon. METHODS: We reviewed 105 consecutive HRAs in 83 patients, performed by a single surgeon, at a mean follow-up of 14.9 years (9.3 to 19.1). The cohort included 45 male and 38 female patients, with a mean age of 49.5 years (SD 12.5). RESULTS: At the time of review 13 patients with 15 hips had died from causes unrelated to the hip operation, and 14 hips had undergone revision surgery, giving an overall survival rate of rate of 86.7% (95% confidence interval (CI) 84.2 to 89.1). The survival rate in men was 97.7% (95% CI 96.3 to 98.9) and in women was 73.4% (95% CI 70.6 to 75.1). The median head size of the failed group was 42 mm (interquartile range (IQR) 42 to 44), and in the surviving group was 50 mm (IQR 46 to 50). In all, 13 of the 14 revised hips had a femoral component measuring ≤ 46 mm. The mean blood levels of cobalt and chromium ions were 26.6 nmol/l (SD 24.5) and 30.6 nmol/l (SD 15.3), respectively. No metal ion levels exceeded the safe limit. The mean Oxford Hip Score was 41.5 (SD 8.9) and Harris Hip Score was 89.9 (14.8). In the surviving group, four patients had radiolucent lines around the stem of the femoral component, and one had lysis around the acetabular component; eight hips demonstrated heterotopic ossification. CONCLUSION: Our results confirm the existing understanding that HRA provides good long-term survival and function in patients with adequate-sized femoral heads. This is evidenced by a 97.7% survival rate among men (larger heads) in our series at a mean follow-up of 14.9 years. Failure is closely related to head sizes ≤ 46 cm. Cite this article: Bone Jt Open 2022;3(1):68-76.

Custom cementless THA in patients with skeletal dysplasia results in lower apparent revision rates than other types of femoral fixation.

BACKGROUND: Patients with skeletal dysplasia are prone to degenerative hip disease thus requiring THA at a younger age than the general population. This is a technically demanding procedure with high complication and revision rates. Achieving good femoral fixation can be challenging because of the abnormal features of the hip. QUESTIONS/PURPOSES: We therefore determined: (1) survivorship, (2) function, (3) radiographic findings, and (4) complications associated with a cementless custom-made femoral component used in THAs for patients with skeletal dysplasia and compared these parameters with those from other types of femoral fixation. PATIENTS AND METHODS: Between 1992 and 2005, 40 THAs were performed in 25 patients with skeletal dysplasia using custom-made cementless femoral components. There were 15 men and 10 women with a mean age of 37.5 years (range, 18-61 years) and a mean height of 145 cm (range, 120-173 cm). Patients were followed clinically and radiographically for a minimum of 4.3 years (mean, 10.1 years; range, 4.3-18.2 years). RESULTS: The survivorship rates for the femoral and acetabular components were 92% and 70%, respectively, at 220 months. Revision arthroplasty was performed in four of 40 hips (10%). In two, the acetabular component was revised for aseptic loosening, one had both components revised for aseptic loosening, and one had an isolated femoral component revision for deep infection. The mean Harris hip score improved from 41 (range, 27-57) preoperatively to 80 (range, 51-94) at final followup. There were two intraoperative proximal femoral fractures and one dislocation. CONCLUSIONS: When compared with studies with equal followup, custom-made cementless components in THAs for patients with skeletal dysplasia apparently had lower revision and complication rates with comparable function and higher midterm survival.

Custom endoprosthetic reconstruction for malignant bone disease in the humeral diaphysis.

The optimal reconstructive method following segmental resection of malignant tumours in the humeral diaphysis is unknown as there are no prospective long-term studies comparing biologic with endoprosthetic reconstruction. This is a retrospective review of 13 patients who, between 1995 and 2010, had undergone limb salvage at our institution using a custom-made humeral diaphyseal endoprosthetic replacement following excision of malignant bone disease. There were 9 males and 4 females with a mean age of 35 years at the time of surgery (range: 10 to 78). Mean follow-up was 56.8 months (range: 5 to 148). Cumulative patient survival was 75% at 10 years. Implant survival, with removal of the endoprosthesis or part of it for any reason as an end point, was 47% at 10 years. Seven patients required revision (54%). Complications included metastases in four, aseptic loosening in four, peri-prosthetic fracture in two and local recurrence in two. Mean MSTS and TESS scores were 23 (18 to 27) and 67% (52-80) respectively. Custom-made humeral diaphyseal replacement following resection of malignant bone tumours provided functional results superior to amputation, without an obvious compromise in patient survival. There was a relatively high revision rate for aseptic loosening and peri-prosthetic fracture and patients should be counselled about this preoperatively.

Outcomes of total hip arthroplasty in haemodialysis and renal transplant patients: systematic review.

BACKGROUND: Chronic renal failure is increasing in prevalence and reported to have deleterious effects on the outcome of total hip arthroplasty (THA). AIM: To investigate the clinical and functional outcomes of THA in patients receiving haemodialysis or who have previously undergone renal transplantation. METHODS: Systematic review of the literature using bibliographic databases up to July 2018 to determine the functional outcome, complications and revision rates of THA in patients receiving haemodialysis for end-stage renal failure and those with a previous renal transplant. RESULTS: 25 studies were identified with a total of 797 THAs. 166 patients (20.8%) were receiving haemodialysis and 631 patients (79.2%) had undergone transplantation. All studies reported a marked improvement in hip function following THA. There were 27 failures (15.7% revision rate) in the haemodialysis group and 101 failures (16.0% revision rate) in the transplant group. The revision rate for cemented implants was higher in haemodialysis versus transplant patients (23% vs. 15%), with the converse being true for uncemented implants (3.8% vs. 6.9%). The deep infection rate was higher in the haemodialysis group (10.8% vs. 2.1%). CONCLUSIONS: Patients receiving haemodialysis or with a history of renal transplantation can expect good functional outcome following THA. However, the revision rate and deep infection rate are higher than would be expected in patients receiving THA for primary OA. Aseptic loosening is the most common reason for revision. Uncemented implants appear to be associated with lower failure rates both in haemodialysis patients and those who have had a transplant.

Functional outcomes, complications and revision rate of hip arthroplasty in patients with sequelae of slipped capital femoral epiphysis: a systematic review.

BACKGROUND: Slipped capital femoral epiphysis (SCFE) results in alterations to femoral head anatomy, predisposing patients to degenerative hip disease at a young age. Total hip arthroplasty (THA) is performed to relieve symptoms and improve function. However, it can be associated with a variable outcomes and little evidence exists on the functional outcomes, complications and revision rate following such procedures. PURPOSE: The aim of this systematic review is to determine the safety and effectiveness of performing hip arthroplasty in patients with degenerative hips secondary to SCFE. METHODOLOGY: A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A literature review was conducted of MEDLINE and Embase. Both single-arm and comparative studies were included. The outcomes of interest were functional scores, post-operative complications and revision rate. RESULTS: Six studies fit the inclusion criteria. Of these, five were retrospective single-arm studies and one was a retrospective comparative study based on registry data.All studies reported significant improvement in hip function and quality of life after THA. An overall revision rate of 11.9% was reported, occurring at a mean of 6.5 years (0.75-18.7 years).THA in patients after SCFE leads to improved functional outcomes that are comparable to patients receiving THA for osteoarthritis. The revision rate appears to be higher than is reported in patients undergoing THA for osteoarthritis at mid-term follow-up. Further prospective comparative studies are needed to evaluate the efficacy of the treatment in more detail. Cite this article: EFORT Open Rev 2021;6:539-544. DOI: 10.1302/2058-5241.6.200038.

Proximal femoral replacements for metastatic bone disease: financial implications for sarcoma units.

Metastatic pathological fractures of the proximal femur are increasingly treated by endoprosthetic proximal femoral replacement. We report the results and the costs incurred performing these procedures at our supra-regional sarcoma unit. Sixty-two patients underwent 63 proximal femoral replacements for metastatic bone disease over a seven-year period. Breast cancer was the most common primary pathology. One patient underwent a revision procedure for infection. Twenty-two patients suffered dislocations, most commonly those undergoing a conventional arthroplasty articulation. The estimated cost of a proximal femoral replacement is 18,002 pounds at our centre. Less than half of this is reimbursed under Payment by Results. Endoprosthetic replacement of the proximal femur is an effective treatment of metastases, but is poorly reimbursed under current funding arrangements.

Modular proximal femoral replacement in salvage hip surgery for non-neoplastic conditions.

Addressing severe proximal femoral bone loss in revision hip surgery is a challenging reconstructive problem. The use of modular proximal femoral megaprostheses is one of many available options to address this. This is a retrospective review of 15 patients who had undergone limb salvage at our institution using a modular proximal femoral replacement. There were 8 males and 7 females with a mean age of 67 years (34 to 85) and a mean follow-up of 60 months (1 to 99). Indications included re-implantation for deep infection in nine patients, aseptic loosening in three, periprosthetic fracture in two and painful excision arthroplasty in one. Mean Harris hip score increased from 28 (13 to 49) pre-operatively to 69 (39 to 85) at final follow-up (paired t-test, p < 0.0001) and mean Toronto Extremity Salvage score increased from 26% (14 to 40) to 71% (35 to 82) (paired t-test, p < 0.0001). Prosthesis survival with revision as the endpoint was 87% at 5 years. There were two dislocations (14%) and there was failure to eradicate deep infection in two. Modular proximal femoral replacement provided good function and versatility with an acceptable complication rate for patients with severe proximal femoral bone loss with or without infection.

Use of three-dimensional printing in preoperative planning in orthopaedic trauma surgery: A systematic review and meta-analysis.

BACKGROUND: With the increasing complexity of surgical interventions performed in orthopaedic trauma surgery and the improving technologies used in three-dimensional (3D) printing, there has been an increased interest in the concept. It has been shown that 3D models allow surgeons to better visualise anatomy, aid in planning and performing complex surgery. It is however not clear how best to utilise the technique and whether this results in better outcomes. AIM: To evaluate the effect of 3D printing used in pre-operative planning in orthopaedic trauma surgery on clinical outcomes. METHODS: We performed a comprehensive systematic review of the literature and a meta-analysis. Medline, Ovid and Embase were searched from inception to February 8, 2018. Randomised controlled trials, case-control studies, cohort studies and case series of five patients or more were included across any area of orthopaedic trauma. The primary outcomes were operation time, intra-operative blood loss and fluoroscopy used. RESULTS: Seventeen studies (922 patients) met our inclusion criteria and were reviewed. The use of 3D printing across all specialties in orthopaedic trauma surgery demonstrated an overall reduction in operation time of 19.85% [95% confidence intervals (CI): (-22.99, -16.71)], intra-operative blood loss of 25.73% [95%CI: (-31.07, -20.40)], and number of times fluoroscopy was used by 23.80% [95%CI: (-38.49, -9.10)]. CONCLUSION: Our results suggest that the use of 3D printing in pre-operative planning in orthopaedic trauma reduces operative time, intraoperative blood loss and the number of times fluoroscopy is used.

Cemented vs. cementless fixation in primary total knee arthroplasty: a systematic review and meta-analysis.

Over 100,000 total knee replacements (TKRs) are carried out in the UK annually, with cemented fixation accounting for approximately 95% of all primary TKRs. In Australia, 68.1% of all primary TKRs use cemented fixation, and only 10.9% use cementless fixation. However, there has been a renewed interest in cementless fixation as a result of improvements in implant design and manufacturing technology.This meta-analysis aimed to compare the outcomes of cemented and cementless fixation in primary TKR. Outcome measures included the revision rate and patient-reported functional scores.MEDLINE and EMBASE were searched from the earliest available date to November 2018 for randomized controlled trials of primary TKAs comparing cemented versus cementless fixation outcomes.Six studies met our inclusion criteria and were analysed. A total of 755 knees were included; 356 knees underwent cemented fixation, 399 underwent cementless fixation. They were followed up for an average of 8.4 years (range: 2.0 to 16.6).This study found no significant difference in revision rates and knee function in cemented versus cementless TKR at up to 16.6-year follow-up. Cite this article: EFORT Open Rev 2020;5:793-798. DOI: 10.1302/2058-5241.5.200030.

Bilateral total hip arthroplasty in ankylosing spondylitis: a systematic review.

Ankylosing Spondylitis (AS) can commonly involve the hip joint and cause significant mobility problems. Total hip arthroplasty (THA) on a single side alone will not restore mobility in patients with bilateral disease.We performed a systematic review of the available literature to determine the changes in objective outcome measures and complications of bilateral THA in patients with advanced AS. Four studies, a total of 114 THAs, were included in the study. The average patient age was 32.9 years and the average follow-up time was 59.5 months.All studies reported a significant improvement in hip function, patient satisfaction and patient mobility following bilateral THA. Harris Hip Score (HHS) improved by a mean of 60.6 points post-operatively.Complications included five intra-operative fractures (4.4%) and three transient nerve palsies (2.6%). There were two dislocations (1.8%) that were successfully managed with closed reduction. Seven hips required revision, with the most common cause being aseptic loosening. Twelve hips (10.5%) developed heterotopic ossification consistent with Brooker Class 1 or 2 with no reports of re-ankylosis.This review suggests that bilateral THA is a safe and effective treatment of advanced hip disease in AS. Attention must be paid to the highly demanding technical aspects of this procedure to reduce the risk of significant complications.Debate still exists on the ideal prosthesis, fixation method and approach to use but this review presents data from several series of uncemented prostheses that have good post-operative results. Cite this article: EFORT Open Rev 2019;4:476-481. DOI: 10.1302/2058-5241.4.180047.

Post-radiation sciatic neuropathy: a case report and review of the literature.

BACKGROUND: Post-radiation peripheral neuropathy has been reported in brachial and cervical plexuses and the femoral nerve. CASE PRESENTATION: We describe a patient who developed post-radiation sciatic neuropathy after approximately 3 years and discuss the pathophysiology, clinical course and treatment options available for the deleterious effects of radiation to peripheral nerves. CONCLUSION: This is the first case of post-radiation involvement of the sciatic nerve reported in the literature.

Late widespread skeletal metastases from myxoid liposarcoma detected by MRI only.

BACKGROUND: Myxoid liposarcoma is the second most commonly occurring sub-type of liposarcomas. In contrast to other soft tissue sarcomas, it is known to have a tendency to spread toward extrapulmonary sites, such as soft tissues, retroperitoneum, and the peritoneal surface. Bony spread, however, is not as common. CASE PRESENTATION: We report an unusual case of diffuse skeletal metastases from myxoid liposarcoma occurring 13 years after treatment of the primary tumour in the left lower limb. The skeletal spread of the disease was demonstrated on MRI only after other imaging modalities (plain radiography, CT and TC99 bone scans) had failed to detect these metastases. CONCLUSION: MRI is an extremely sensitive and specific screening tool in the detection of skeletal involvement in these types of sarcomas, and therefore, should be a part of the staging process.

Total knee arthroplasty in patients with Paget's disease of bone: A systematic review.

AIM: To determine the functional outcomes, complications and revision rates following total knee arthroplasty (TKA) in patients with Paget's disease of bone (PDB). METHODS: A systematic review of the literature was performed. Four studies with a total of 54 TKAs were included for analysis. Functional outcomes, pain scores, complications and revision rates were assessed. The mean age was 72.0 years and the mean follow-up was 7.5 years. RESULTS: All studies reported significant improvement in knee function and pain scores following TKA. There were 2 cases of aseptic loosening, with one patient requiring revision of the femoral component 10 years after the index procedure. Malalignment, bone loss, soft tissue contractures were the most commonly reported intra-operative challenges. There were five cases (9%) that were complicated by intra-operative patellar tendon avulsion. CONCLUSION: The findings support the use of TKA in patients with PDB. The post-operative functional outcomes are largely similar to other patients, however there are specific perioperative challenges that have been highlighted, in particular the high risk for patellar tendon avulsion.

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.