High tibial osteotomy versus unicompartmental knee arthroplasty in advanced medial compartmental knee arthrosis: A comparative study with propensity score matched analysis.

BACKGROUND: Isolated knee medial compartmental osteoarthritis(MOA) can be treated with High Tibial Osteotomy (HTO) or Unicompartmental Knee Arthroplasty (UKA). This study aims to describe and compare outcomes of HTO and UKA in patients with isolated severe MOA. The authors hypothesized that similar outcomes can be achieved. METHODS: Data was collected prospectively of HTOs and UKAs performed between January-2016 and April-2021 by a knee surgeon. Oxford Knee Score (OKS), Knee Society Knee Score (KSKS) and Function Score (KSFS) were collected pre-operatively, six-months and two-years post-surgery. OA severity was graded on pre-operative radiograph. Medial Proximal Tibia Angle (MPTA), Lateral Distal Femoral Angle (LDFA), Joint Line Convergence Angle (JLCA) and Hip-Knee-Ankle Angle (HKAA), were measured on full-length radiograph. 47 HTO and 74 UKA were included. Propensity score matching was performed, accounting for preoperative scores, age, gender and body mass index (BMI), before statistical analysis. Level of significance was set at 0.05. RESULTS: Both groups were similar in age(56.42 vs 58.57, p = 0.067), BMI(29.82 vs 29.09, p = 0.484), gender distribution (p = 0.663) and laterality (p = 0.836). Pre-operatively, both groups were similar in clinical scores and lower limb alignment. On follow-up, both groups achieved similar improvements in clinical scores. However, the HTO group reported poorer extension at 6-months (7.91° vs 4.80°, p = 0.013) and 2-years (5.57° vs 3.24°, p = 0.018). Three cases of hinge fracture and six cases of implant removal occurred in the HTO group. One case of tibial fracture occurred in the UKA group. CONCLUSIONS: In severe MOA, similar outcomes were achieved with HTO and UKA at two years.

Faster Bone Gap Union in Medial Opening Wedge High Tibial Osteotomy With 3D-Printed Synthetic Bioresorbable Polycaprolactone and Tricalcium Phosphate Osteotomy Gap Fillers Compared to Allogeneic Osteotomy Gap Fillers: A Retrospective Matched-Pair Cohort Study.

OBJECTIVE: The use of synthetic bone substitute material (BSM) as osteotomy gap fillers have been reported to improve outcomes in medial opening wedge high tibial osteotomy (MOWHTO). This study aims to evaluate the early radiological outcomes (bone union) and complication rates of the novel patient-specific 3D-printed honeycomb-structured polycaprolactone and tricalcium phosphate (PCL-TCP) synthetic graft compared to allogeneic bone grafts as an osteotomy gap filler in MOWHTO. METHODS: A retrospective matched-pair analysis of patients who underwent MOWHTO with either PCL-TCP synthetic graft or allogenic femoral head allograft as osteotomy gap filler was performed. The osteotomy gap was split into equal zones (Zone 1-5), and bone union was evaluated on anteroposterior radiographs based on the van Hemert classification at 1, 3, 6, and 12 months postoperatively. Postoperative complications including infection, lateral hinge fractures, and persistent pain was measured. The study and control group were matched for age, smoking status, diabetes mellitus, and osteotomy gap size. RESULTS: Significantly greater bone union progression was observed in the PCL-TCP group than in the allograft group at 1 month (Zones 1-3), 3 months (Zones 1-4), 6 months (Zones 1-2, 4), and 12 months (Zones 2-3, 5) postoperatively (P < 0.05). No significant difference in complications rates was noted between the two groups at 1 year. CONCLUSIONS: Bone union rates observed in patients who underwent MOWHTO with the PCL-TCP synthetic graft osteotomy gap filler were superior to those in the allograft group at 1 year postoperatively, with no significant difference in complication rates (postoperative infection, lateral hinge fractures, and persistent pain).

No significant post-operative limb length difference following medial opening wedge high tibial osteotomy in a multi-ethnic Southeast Asian population.

PURPOSE: This study aims to assess the significance of post-operative change in limb length in medial opening wedge high tibial osteotomy (MOWHTO), and evaluate the correlation between correction angles and changes in limb length. We hypothesize that opening wedge height and correction angles directly correlate to changes in limb length. METHODS: The medical records and radiographs of 91 MOWHTO patients were retrospectively evaluated for relevant radiographical parameters both pre- and post-operatively. The exclusion criteria are: (i) concurrent distal femur osteotomy in the same setting, (ii) other previous unilateral lower limb surgeries prior to MOWHTO and (iii) failure to follow-up with post-operative radiographs. A linear regression model was performed and a line of best fit, Pearson's correlation coefficient (r) and coefficient of determination (R2) were computed. Chi-squared test was also performed, and results with P < 0.05 were considered statistically significant. RESULTS: There is a statistically significant increase in post-MOWHTO limb length (Absolute Δ = 4.3 ± 2.86 mm, % Δ = 0.652% ± 0.434%, p < 0.001). There was no significant difference in the limb length change between patients with larger (> 8 mm) and smaller (< 8 mm) opening widths. There was a weakly positive correlation between limb length change versus actual (R2 = 0.140, 95%CI [-0.068, 0.336]) and planned correction angles (R2 = 0.196, 95%CI [-0.012, 0.387]). CONCLUSION: In conclusion, post-MOWHTO change in limb length is statistically significant, but the clinical significance is minimal. Further studies are required to assess other factors. Development of a reliable mathematical model that predicts post-MOWHTO limb length change would be useful in predicting the anatomical outcomes. LEVEL OF EVIDENCE: Level III. Retrospective Cohort Study.

Large Versus Small Opening Wedge High Tibial Osteotomies Performed With a Protective Wire Over the Lateral Hinge: Incidence of Lateral Hinge Fracture and Early Clinical Outcomes.

BACKGROUND: The incidence of lateral hinge fractures (LHFs) during medial opening wedge high tibial osteotomy (MOW-HTO) is unacceptably high, especially with distractions >10 mm. LHFs result in malunion, loss of correction, and recurrence of symptoms adversely affecting clinical outcomes. PURPOSE: (1) To investigate the incidence of LHF when a protective guide wire is utilized during MOW-HTO in small and large corrections and (2) to study the effect of correction size on early clinical outcomes. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A retrospective analysis was performed of 96 knees that underwent MOW-HTO between 2019 and 2020. A protective wire applied intraoperatively across the lateral hinge point before opening wedge distraction was performed for all patients. Patients were divided into 2 groups based on opening wedge sizes: group A (opening distraction <10 mm) and group B (opening distraction ≥10 mm). LHF and wound complications were recorded. Prospective Knee Score and Function Score (Knee Society), Oxford Knee Score, and Physical and Mental Component Summaries of the 36-Item Short Form Health Survey questionnaire were recorded preoperatively and at 6 months and 2 years after surgery. RESULTS: Incidence of LHF was low in group A (n = 2; 6.1%) and group B (n = 3; 9.1%). A single case of intraoperative LHF was noted in each group, with each case resulting in a type 1 fracture. The incidence of postoperative fractures was comparable between groups (groups A vs B, n = 1 vs 2). At 6 months, clinical outcomes in group A were superior to those of group B (Knee Score, 85.7 ± 14.7 vs 73.1 ± 20.3, P = 0.028; Function Score, 73.5 ± 16.5 vs 63.1 ± 19.5, P = 0.047; Oxford Knee Score, 20.2 ± 4.7 vs 25.6 ± 8.5, P = 0.008; Physical Component Summary, 46.8 ± 8.1 vs 40.2 ± 10.9, P = 0.018). However, clinical outcomes were comparable at 2 years (P > .05). CONCLUSION: A protective wire was associated with a low incidence of LHF, even in larger MOW-HTO corrections. Large corrections had poorer clinical outcomes as compared with small corrections at 6 months. However, clinical outcomes between groups were comparable at 2 years.

Distalization of hinge site with use of hinge wire reduces hinge fracture rates in closing wedge distal femoral osteotomy.

PURPOSE: Closing wedge distal femoral osteotomies (CWDFO) are attractive treatment options for unicompartmental knee osteoarthritis with coronal plane deformity. However, it has been traditionally associated with high rates of hinge fracture that can adversely impact recovery and patient outcomes. Appropriate siting of hinge point can be an effective method of reducing the incidence of hinge fractures. This study aims to illustrate a case series of CWDFO with low rates of hinge fracture utilising our preferred hinge point site. METHODS: A retrospective study of a cohort of 39 CWDFO was performed between May 2019 and May 2022. Both medial and lateral CWDFO were included. The hinge point in all cases was placed at the level of the inferior margin of the metaphyseal flare, and inferior to the gastrocnemius origin, with a hinge thickness of 10 mm. Post-operative radiographs were obtained at 2, 4 and 8 weeks after surgery to assess for hinge fracture and union. RESULTS: Thirty-nine cases of CWDFO were performed, consisting of eighteen cases of valgus malalignment that underwent medial CWDFO and twenty-one cases of varus malalignment that underwent lateral CWDFO. At surgery, the mean age was 47.6 (± 13.9) years and mean BMI was 29.4 (± 4.9). There were 23 men and 16 women. Three cases of hinge fractures occurred intraoperatively, translating into a hinge fracture rate of 7.69%. However, union was achieved in all three cases and all patients in this case series were able to progress to weight bear as tolerated at 2 months post-osteotomy. CONCLUSION: Distal placement of the hinge at the level of the inferior metaphyseal flare margin with the use of a hinge wire can greatly reduce the rates of hinge fracture in CWDFO. LEVEL OF EVIDENCE: Level III.

Alignment prior to total knee arthroplasty in high tibial osteotomy patients has no effect on subsequent functional outcomes.

INTRODUCTION: The influence of prior high tibial osteotomy (HTO) on total knee arthroplasty (TKA) functional outcomes remains widely debated. Alignment of failed HTO can pose technical challenges with subsequent TKA. The primary aim of this study was to evaluate the influence of HTO alignment on the clinical outcomes of subsequent TKA. The secondary aim was to compare the time to TKA for each HTO alignment type. METHODS: Patients who underwent TKA post lateral closing-wedge HTO for symptomatic medial compartment osteoarthritis between 2001 and 2014 were prospectively followed up for 2 years. A total of 159 patients were assigned to three groups based on their pre-TKA femora tibia angles using long lower limb radiographs: varus alignment (VrA) ≤ 3o valgus, neutral alignment (NA) 3-9o valgus alignment, valgus alignment (VlA) ≥ 9o valgus. Functional outcomes were quantified using Knee Society Function Score and Knee Scores (KSFS and KSKS respectively), modified Oxford Knee Score (OKS), Short Form 36 Physical Component Score (SF-36 PCS), and SF-36 Mental Component Score (SF-36 MCS). Pre-operative and post-operative knee range of motion were also measured. RESULTS: Mean pre-TKA KSKS in VrA patients (35 ± 18) was significantly lower than both NA (51 ± 19) and VlA (40 ± 21) patients (p < .05). Otherwise, there was no significant difference in functional outcome scores (KSFS, KSKS, OKS, SF-36 PCS and SF-36 MCS) or range of motion at 6 months and 2 years post-TKA. The mean duration from HTO to TKA was 12 ± 7 years with no significant differences between VrA, NA, and VlA HTO to TKA (13 ± 7 years, 13 ± 6 years and12 ± 8 years respectively, p > .05). CONCLUSION: HTO alignment did not influence time to subsequent TKA. HTO alignment did not influence early outcomes as well as radiological outcomes of subsequent TKA. LEVEL OF EVIDENCE: III.

Radiofrequency Plantar Fascia Coblation With and Without Gastrocnemius Recession in the Management of Recalcitrant Plantar Fasciitis.

BACKGROUND: Plantar fasciitis is the most common cause of plantar heel pain. Although most are self-limiting, recalcitrant conditions can be debilitating, significantly reducing patient's quality of life. A myriad of surgical procedures are available for the treatment of recalcitrant plantar fasciitis (RPF) with little consensus on best practice. This purpose of this study was to assess the efficacy of radiofrequency coblation with and without gastrocnemius release on the surgical management of RPF. METHODS: Between June 2013 and June 2019, a total of 128 patients with RPF and tight gastrocnemius were treated surgically. Presence of tight gastrocnemius was assessed clinically by a positive Silfverskiold test. Group A (n = 73) consisted of patients who underwent radiofrequency coblation alone; group B (n = 55) consisted of patients who underwent radiofrequency coblation and endoscopic gastrocnemius recession. The primary outcome measure was visual analog scale (VAS) score. Secondary outcome measures included (1) American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score; (2) physical (PCS) and mental component summaries (MCS) of the 36-Item Short Form Health Survey; (3) overall assessment of improvement, expectation fulfilment, and satisfaction; and (4) complication rates. RESULTS: Both groups reported significant improvement in VAS, AOFAS, and PCS scores postoperatively at 6 and 24 months. Group B (radiofrequency coblation with gastrocnemius recession) was associated with better VAS at both 6 months (3.0 ± 2.9 vs 1.7 ± 2.6, P < .05) and 24 months postoperatively (1.9 ± 3.1 vs 0.8 ± 2.0, P < .05) compared with group A (radiofrequency coblation without gastrocnemius recession). At 24 months postoperatively, no differences were found in AOFAS, PCS, MCS scores, expectation fulfilment, or overall satisfaction. No wound complications were reported in either group. One patient (group B) has persistent symptoms consistent with tarsal tunnel syndrome. CONCLUSION: In this retrospective cohort comparative study, treatment of RPF with radiofrequency coblation alone was associated with slightly inferior results than radiofrequency coblation combined with endoscopic gastrocnemius recession in terms of pain relief without an increase in complication rates. However, at 2 years, we did not find a significant difference in other measures of outcome. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Association of Elevated Body Mass Index and Outcomes of Arthroscopic Treatment for Osteochondral Lesions of the Talus.

Background: Osteochondral lesions of the talus (OLTs) are a common condition found in patients with chronic ankle pain after previous ankle sprains. Surgical management is indicated after conservative management has failed. Hypothesis/Purpose: This study evaluates the influence of body mass index (BMI) on the early clinical outcomes of arthroscopic debridement and microfracture of OLTs. Methods: A total of 252 patients with symptomatic OLTs who failed conservative management underwent arthroscopic debridement and microfracture of OLTs over the affected ankle between 2007 and 2017. Patients from this cohort were divided into 2 groups based on BMI: the normal BMI group (NB Group) (BMI 18.5-25.0) and overweight and obese BMI group (OB Group) (BMI ≥25). Visual analogue scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, and the physical and mental component summaries of the 36-Item Short-Form Health Survey (PCS and MCS, respectively) were prospectively collected from the cohort during their standard postoperative outpatient follow-up. Results: The NB Group (n=105) and OB Group (n=147) were well matched demographically. The operative duration was significantly shorter for the NB Group compared to the OB Group. Patients from both groups had significant improvements in VAS, AOFAS, and PCS scores postoperatively at 6 and 24 months after surgery (P < .05). Between both groups, patients had comparable VAS, AOFAS, and PCS scores at preoperation, 6 months postoperation, and 24 months postoperation (P > .05). However, MCS in the OB Group was lower at 24 months postoperatively compared with the NB Group (P < .05). The OB Group reported better satisfaction scores (82.4% vs 72.6%, P < .05), and a greater proportion had their expectations met (88.2% vs 77.9%, P < .05). Conclusion: A BMI ≥25 was not associated with worse postoperative pain and functional outcomes, but rather was found to be associated with greater satisfaction and fulfillment. However, patients with BMI ≥25 required longer procedure duration and had poorer MCS scores at 24 months after surgery.Level of Evidence: Level III, retrospective cohort study.

Medial Meniscal Allograft Transplantation With Bone Plugs Using a 3-Tunnel Technique.

Meniscal allograft transplantation is an area of active research, given that the importance of the meniscus in native knee joint longevity has been increasingly recognized. This article describes a modified meniscal allograft transplantation technique using 3 bone tunnels with allograft fixation through the use of bone plugs. The addition of a third tunnel increases the strength of fixation, avoiding meniscal extrusion and improving load distribution.

Vancomycin-soaked femoral head allograft in opening wedge high tibia osteotomy enables earlier postoperative recovery and reduces infection rates compared to allogenic bone chips.

PURPOSE: To investigate the benefits of vancomycin-soaked femoral head allograft versus allogenic bone chips as an osteotomy gap filler in reducing infection rates and perioperative pain control after medial opening wedge high tibial osteotomy (MOW-HTO). METHODS: Retrospective analysis of 114 knees that underwent MOW-HTO between 2013 and 2020. Osteotomy gaps were filled with vancomycin-soaked femoral head allograft (Study Group) or allogenic bone chips (Control Group). Both groups received systemic antibiotics. Perioperative parameters studied included pain, blood loss, length of stay, postoperative day (POD1) pain scores at rest, with activity as well as ambulatory distance. Patients in the Study Group were also followed up prospectively and clinical outcome scores, namely Knee Society Score, Oxford knee score (OKS) and Physical and Mental Component of the Short-Form 36 Questionnaire (PCS and MCS, respectively). Statistical analyses using Student's T-test were performed between the groups. RESULTS: Patients of the study group had significantly better POD1 visual analogue scale (VAS) at rest (0.9 ± 1.6 vs 2.9 ± 1.2, p < 0.001) as well as when active (3.0 ± 1.9 vs 5.8 ± 1.5, p < 0.001). A greater proportion of patients in the study group ambulated on POD 1, (90.6% vs 26.0%, p < 0.001). Of those who ambulated on POD1, study group patients managed to cover a greater ambulatory distance (13.9 ± 7.4 m vs 8.4 ± 9.3 m, p < 0.05). The proportion of study group patients requiring patient-controlled analgesia (PCA) was also significantly less compared to the control group (32.8% vs 58.0%, p < 0.05). Of those requiring PCA, the amount of morphine requirement was also significantly reduced in the group with vancomycin-soaked allograft (8.7 ± 8.1 mg vs 23.9 ± 33.0 mg, p < 0.05). The study group also had a reduced length of stay (3.5 ± 2.0 days vs 5.5 ± 2.6 days, p < 0.001). Patients in the study group demonstrated significant improvement in Knee Society Knee Score (KSKS), OKS, PCS and MCS at 12 months postoperatively. The study group had a significantly reduced incidence of superficial wound infections compared to the control group (3.1% vs 18.0%, p < 0.05). CONCLUSION: Vancomycin-soaked femoral head allograft reduced superficial and deep wound infections in MOW-HTO. It was also effective in reducing postoperative pain, thereby enabling early ambulation and shorter hospital stays. LEVEL OF EVIDENCE: Retrospective comparative study, III.

Mid-Term Functional and Radiological Outcomes of Total Ankle Replacement in an Asian Cohort.

There are limited studies looking at longer-term outcomes of the total ankle replacement (TAR) in the Asian cohort. Asian ankles are smaller in size and are more varus compared to Western cohorts. Cultural differences also require increased ankle range of motion demands. Therefore, assessment of longer-term functional and radiological outcomes in the Asian cohort is warranted. Between 2007 and 2015, 43 consecutive patients received a 3-component, cementless, unconstrained, fully congruent TAR. Patients were followed up over a mean 8 (range 5-14 years). Preoperative and postoperative AOFAS ankle-hindfoot score (AOFAS-AHS), visual analogue score (VAS), physical and mental component scores of the SF-36 (PCS and MCS respectively) were calculated. European Foot and Ankle Score was also recorded at 8 years. Radiographs were reviewed postoperatively to assess implant position and study evidence of implant loosening and impingement. At 8 years, survivorship was 83.5%. Reasons for implant removal included infection (n = 2) and aseptic loosening (n = 5). AOFAS-AHS, VAS MCS at 8 years postoperatively were comparable to outcomes at 2 years postoperatively (p > .05). PCS at 8 years demonstrated improvement compared to 2 years postoperatively (49 ± 7 vs 42 ± 11, p = .048). Radiographic impingement was noted in 9 cases (20.9%). Radiological loosening was noted in 8 cases with 5 cases requiring revision surgery. At 8 years postoperatively, clinical outcomes, radiological outcomes and survivorship following TAR in an Asian cohort are satisfactory and comparable to that found in existing literature. Long-term studies are required to ascertain survivorship of TAR. Implant design with the Asian cohort in mind may yield improved outcomes.

Hallux Varus Correction With Extensor Hallucis Longus Tendon Transfer and Reverse Scarf Osteotomy.

INTRODUCTION: Hallux varus is the medial deviation of the hallux. Although rare, it can cause discomfort, functional weakness, difficulty with shoe wear, and dissatisfactory cosmesis. This study reports 3 cases of hallux varus treated using extensor hallucis longus (EHL) tendon transfer with or without the use of reverse scarf osteotomy (RSO). METHODS: This cases series studies the technique of using EHL tendon transfer and the role for RSO in the surgical correction of hallux varus. Indication for RSO included osseous overcorrection in the index hallux valgus surgery or as an adjunct when EHL tendon transfer alone was unable to restore alignment. Patients were followed-up for 24 months and their postoperative outcomes were recorded. RESULTS: All patients were female between the ages 55 to 67 years. Radiological parameters after surgery improved in all patients. The mean hallux-valgus angle was corrected from -23.7 ± 3.5° to -3.2 ± 2.0° postoperatively (P < .05). Intermetatarsal angle was increased from 5.0 ± 1.9° to 6.7 ± 1.0° (P = .065). Distal metatarsal articular angle improved from -28.9 ± 7.6° to -7.8 ± 3.7° (P < .05). Mean American Orthopaedic Foot and Ankle Society scores improved from 37 ± 24 to 75 ± 9 (P = .064) at 24 months. In addition, visual analogue scale pain scores reduced from 5 ± 1.5 to 1 ± 1 (P < .05). All patients reported being satisfied with the procedure, and no complications were reported at 24 months after surgery. CONCLUSION: Hallux varus correction using EHL tendon transfer with or without RSO appears to provide satisfactory results at 24 months. LEVELS OF EVIDENCE: Level V: Expert opinion, Techniques.

Kinematic aligned femoral rotation leads to greater patella tilt but similar clinical outcomes when compared to traditional femoral component rotation in total knee arthroplasty. A propensity score matched study.

PURPOSE: External rotation of femoral component in total knee arthroplasty (TKA) with reference to the posterior condyles is recommended in mechanical alignment (MA) to ensure optimum patella tracking. In kinematic knee alignment (KA) technique, femoral component is more internally rotated as the femoral resection is based on flexion-extension axis. This study aims to investigate the clinical and radiological outcomes of the patellofemoral joint in patients who underwent TKA using KA versus mechanical alignment. METHODS: A review of prospectively collected registry data of 378 consecutive cruciate retaining primary TKAs (P.F.C.® Total Knee System, DePuy Synthes, Massachusetts, United States) was performed. Propensity scoring was performed matching patients who received KA TKA (n = 93) to MA TKA (n = 93). Oxford Knee Score (OKS), Knee Society Score (KSS), Short-Form 36 (SF-36), range of motion as well as radiographs assessing patella tilt were compared at 6 months and 2 years after surgery. All patients received the same implant and had their patella resurfaced. RESULTS: OKS, KSS, physical component of SF-36 and satisfaction rates were comparable at both 6 months and 2 years after surgery. There was moderate association between preoperative and postoperative patella tilt in KA TKA (Cramer's V = 0.260, p < 0.05). Postoperatively, KA group had a greater number of patients with lateral patella tilt compared to the mechanical group (12 [12.9%] vs 1 [1.1%], p < 0.001). Patella tilts, however, resolved two years after surgery. CONCLUSION: The relative internal rotation of the femoral component in KA TKA results in greater incidence of lateral patella tilt postoperatively. Nevertheless, patella tilt resolution was noted at 2 years. LEVEL OF EVIDENCE: Level III Evidence-Retrospective Cohort Study.

Functional outcome and quality of life in patients with hip fracture after total knee arthroplasty.

INTRODUCTION: Hip fractures are a cause of significant morbidity. While rare, ipsilateral hip fractures within 12 months after total knee arthroplasty (TKA) can negatively affect the functional outcome and the quality of life for patients who have had TKA. This aim of this study is to investigate (1) the incidence of hip fracture within 12 months after TKA and (2) the influence of hip fracture after TKA on functional outcome and quality of life in patients. METHODS: Between March 1999 and February 2012, 25 patients who sustained an ipsilateral hip fracture within 12 months after TKA were included in this study. A propensity score matching algorithm was used to select a 1:3 control group without hip fracture. All patients were assessed using the Oxford Knee Score (OKS), Knee Society Function Score (KSFS), Knee Society Knee Score (KSKS), Physical Component Score (PCS) and Mental Component Score (MCS) of SF-36®. RESULTS: The incidence of hip fracture was 0.16% among male patients and 0.20% for female patients. At 24 months after TKA, the OKS was 36 ± 7 in the hip fracture group versus 41 ± 5 in the control group (p = 0.003). The KSFS was 50 ± 24 in the hip fracture group versus 68 ± 21 in the control group (p = 0.001), while the KSKS was 83 ± 12 and 87 ± 8, respectively (p = 0.166). The PCS was 37 ± 12 in the hip fracture group versus 47 ± 11 in the control group (p < 0.001), while the MCS was 55 ± 10 and 54 ± 11, respectively (p = 0.664). CONCLUSION: Although hip fracture during the rehabilitation period after TKA is uncommon, these patients have poorer functional outcome and quality of life. We recommend additional caution against hip fracture after TKA.