Total knee arthroplasty after distal femoral osteotomy long-term survivorship and clinical outcomes.

AIMS: There is little literature about total knee arthroplasty (TKA) after distal femoral osteotomy (DFO). Consequently, the purpose of this study was to analyze the outcomes of TKA after DFO, with particular emphasis on: survivorship free from aseptic loosening, revision, or any re-operation; complications; radiological results; and clinical outcome. PATIENTS AND METHODS: We retrospectively reviewed 29 patients (17 women, 12 men) from our total joint registry who had undergone 31 cemented TKAs after a DFO between 2000 and 2012. Their mean age at TKA was 51 years (22 to 76) and their mean body mass index 32 kg/m2 (20 to 45). The mean time between DFO and TKA was ten years (2 to 20). The mean follow-up from TKA was ten years (2 to 16). The prostheses were posterior-stabilized in 77%, varus-valgus constraint (VVC) in 13%, and cruciate-retaining in 10%. While no patient had metaphyseal fixation (e.g. cones or sleeves), 16% needed a femoral stem. RESULTS: The ten-year survivorship was 95% with aseptic loosening as the endpoint, 88% with revision for any reason as the endpoint, and 81% with re-operation for any reason as the endpoint. Three TKAs were revised for instability (n = 2) and aseptic tibial loosening (n = 1). No femoral component was revised for aseptic loosening. Patients under the age of 50 years were at greater risk of revision for any reason (hazard ratio 7; p = 0.03). There were two additional re-operations (6%) and four complications (13%), including three manipulations under anaesthetic (MUA; 10%). The Knee Society scores improved from a mean of 50 preoperatively (32 to 68) to a mean of 93 postoperatively (76 to 100; p < 0.001). CONCLUSION: A cemented posterior-stabilized TKA has an 88% ten-year survivorship with revision for any reason as the endpoint. No femoral component was revised for aseptic loosening. Patients under the age of 50 years have a greater risk of revision. The clinical outcome was significantly improved but balancing the knee was challenging in 13% of TKAs requiring VVC. Overall, 10% of TKAs needed an MUA, and 6% of TKAs were revised for instability. Cite this article: Bone Joint J 2019;101-B:660-666.

Lumbar fusion involving the sacrum increases dislocation risk in primary total hip arthroplasty.

AIMS: Concurrent hip and spine pathologies can alter the biomechanics of spinopelvic mobility in primary total hip arthroplasty (THA). This study examines how differences in pelvic orientation of patients with spine fusions can increase the risk of dislocation risk after THA. PATIENTS AND METHODS: We identified 84 patients (97 THAs) between 1998 and 2015 who had undergone spinal fusion prior to primary THA. Patients were stratified into three groups depending on the length of lumbar fusion and whether or not the sacrum was involved. Mean age was 71 years (40 to 87) and 54 patients (56%) were female. The mean body mass index (BMI) was 30 kg/m2 (19 to 45). Mean follow-up was six years (2 to 17). Patients were 1:2 matched to patients with primary THAs without spine fusion. Hazard ratios (HR) were calculated. RESULTS: Dislocation in the fusion group was 5.2% at one year versus 1.7% in controls but this did not reach statistical significance (HR 1.9; p = 0.33). Compared with controls, there was no significant difference in rate of dislocation in patients without a sacral fusion. When the sacrum was involved, the rate of dislocation was significantly higher than in controls (HR 4.5; p = 0.03), with a trend to more dislocations in longer lumbosacral fusions. Patient demographics and surgical characteristics of THA (i.e. surgical approach and femoral head diameter) did not significantly impact risk of dislocation (p > 0.05). Significant radiological differences were measured in mean anterior pelvic tilt between the one-level lumbar fusion group (22°), the multiple-level fusion group (27°), and the sacral fusion group (32°; p < 0.01). Ten-year survival was 93% in the fusion group and 95% in controls (HR 1.2; p = 0.8). CONCLUSION: Lumbosacral spinal fusions prior to THA increase the risk of dislocation within the first six months. Fusions involving the sacrum with multiple levels of lumbar involvement notably increased the risk of postoperative dislocation compared with a control group and other lumbar fusions. Surgeons should take care with component positioning and may consider higher stability implants in this high-risk cohort.

Total hip arthroplasty in patients affected by poliomyelitis.

Aims: The aims of this study were to determine the clinical and radiographic outcomes, implant survivorship, and complications of patients with a history of poliomyelitis undergoing total hip arthroplasty (THA) in affected limbs and unaffected limbs of this same population. Patients and Methods: A retrospective review identified 51 patients (27 male and 24 female, 59 hips) with a mean age of 66 years (38 to 88) and with the history of poliomyelitis who underwent THA for degenerative arthritis between 1970 and 2012. Immigrant status, clinical outcomes, radiographic results, implant survival, and complications were recorded. Results: In all, 32 THAs (63%) were performed on an affected limb, while 27 (37%) were performed on an unaffected limb. The overall ten-year survivorship free from aseptic loosening, any revision, or any reoperation were 91% (95% CI 0.76 to 0.99), 91% (95% CI 0.64 to 0.97) and 87% (95% CI 0.61 to 0.95), respectively. There were no revisions for prosthetic joint infection. There were no significant differences in any of the above parameters if THA was on the affected or unaffected control limbs. Conclusion: Patients with a history of poliomyelitis who undergo THA on the affected or unaffected limbs have similar results with overall survivorship and complication rates to those reported results in patients undergoing THA for osteoarthritis. At long-term follow-up, previous clinical concerns about increased hip instability due to post-polio abductor weakness were not observed. Cite this article: Bone Joint J 2018;100-B:733-9.

The analysis of synovial fluid in total knee arthroplasties with flexion instability.

AIMS: Patients with flexion instability after total knee arthroplasty (TKA) often present with a recurrent effusion, which may be a haemarthrosis. While the radiographic factors contributing to flexion instability have been elucidated, the clinical diagnosis remains challenging. Our aim, in this study, was to determine the mean white cell count and differential profile in pre-operative aspirations of synovial fluid in a consecutive series of patients undergoing revision TKA for flexion instability. PATIENTS AND METHODS: Between 2000 and 2010, 60 patients undergoing aseptic revision TKA for flexion instability were identified. The results of the pre-operative aspiration of synovial fluid were available for 53 patients (88%). These patients were 1:2 matched to 106 patients who underwent aseptic TKA for indications other than flexion instability. The mean age of the patients at revision TKA was 65 years (44 to 82) and 55% were women. The mean follow-up was 4.3 years (2 to 10.2). RESULTS: In the flexion instability group, the median total cell count was 312 cells/µL (interquartile range (IQR) 104 to 624), with a mean distribution of 45% macrophages (2% to 90%), 30% lymphocytes (1% to 69%), 18% neutrophils (0% to 80%), 0.5% eosinophils (0% to 6%) and 7% other cells (0% to 42%; mainly synovial cells). There was no significant difference in the median total cell count (p = 0.14) or mean distribution of macrophages (p = 0.42), lymphocytes (p = 0.38), neutrophils (p = 0.19) and eosinophils (p = 0.89) between the flexion instability and control groups. There was a significant difference in the percentage of bloody serosanguineous aspirations which was 58% in the flexion instability group and 18% in the control group (odds ratio = 6.5; p = 0.0001). CONCLUSIONS: In the group of patients who underwent revision TKA for flexion instability, most had a mean cell count and differential similar to those who underwent revision for other aseptic indications. However, bloody serosanguineous aspirations were 6.5 times more common in those with flexion instability confirming that many of the recurrent effusions seen in this condition are haemarthroses. Cite this article: Bone Joint J 2017;99-B:1477-81.

Proximal femoral replacement in contemporary revision total hip arthroplasty for severe femoral bone loss: a review of outcomes.

AIMS: Loss or absence of proximal femoral bone in revision total hip arthroplasty (THA) remains a significant challenge. While the main indication for the use of proximal femoral replacements (PFRs) is in the treatment of malignant disease, they have a valuable role in revision THA for loosening, fracture and infection in patients with bone loss. Our aim was to determine the clinical outcomes, implant survivorship, and complications of PFRs used in revision THA for indications other than malignancy. PATIENTS AND METHODS: A retrospective review of 44 patients who underwent revision THA using a PFR between 2000 and 2013 was undertaken. Their mean age was 79 years (53 to 97); 31 (70%) were women. The bone loss was classified as Paprosky IIIB or IV in all patients. The mean follow-up was six years (2 to 12), at which time 22 patients had died and five were lost to follow-up. RESULTS: The mean Harris Hip Score improved from 42.8 (25.9 to 82.9) pre-operatively to 68.5 (21.0 to 87.7) post-operatively (p = 0.0009). A total of two PFRs had been revised, one for periprosthetic infection eight years post-operatively and one for aseptic loosening six years post-operatively. The Kaplan-Meier survivorship free of any revision or removal of an implant was 86% at five years and 66% years at ten years. A total of 12 patients (27%) had a complication including six with a dislocation. CONCLUSION: PFRs provide a useful salvage option for patients, particularly the elderly with massive proximal femoral bone loss who require revision THA, with significant clinical improvement. While the survivorship of the implant is good at five years, dislocation continues to be the most common complication. The judicious use of larger femoral heads, dual-mobility constructs, or constrained liners may help to minimise the risk of dislocation. Cite this article: Bone Joint J 2017;99-B:325-9.

The obese patient: a problem of larger consequence.

Obesity is a worldwide epidemic that has both economic and health implications of enormous consequence. The obese patients tend to have earlier symptoms related to osteoarthritis, more peri-operative medical problems, higher rates of infection and more technical difficulties intra-operatively following hip and knee arthroplasty. Nevertheless, these patients have good long-term clinical outcomes and implant survival rates and are often some of the most satisfied patients after joint arthroplasty. Therefore, obese patients should not be denied surgery based on their weight alone.

Hip dysplasia in the young adult: an osteotomy solution.

The treatment of hip dysplasia should be customised for patients individually based on radiographic findings, patient age, and the patient's overall articular cartilage status. In many patients, restoration of hip anatomy as close to normal as possible with a PAO is the treatment of choice.