Comparison of Long-Term Survival Analysis Between Open-Wedge High Tibial Osteotomy and Unicompartmental Knee Arthroplasty.

BACKGROUND: To compare unicompartmental knee arthroplasty (UKA) and open-wedge high tibial osteotomy (OWHTO) in a long-term follow-up propensity score matching analysis. METHODS: Patients who underwent UKA or OWHTO for unilateral medial unicompartmental osteoarthritis (OA) between 2004 and 2010 were included. The ROM, HSS score, KS score, WOMAC score, forgotten joint score, OA progression in patellofemoral and lateral compartments, and survivorship were compared within ten years of follow-up between 67 UKA and 67 OWHTO patients after propensity score matching for age, gender, body mass index, range of motion, and osteoarthritis (OA) grade. RESULTS: At the last follow-up, there were no significant differences between the two groups in clinical outcomes, but the WOMAC score showed better results after UKA (13.1 in UKA vs 18.9 in OWHTO, P = .011). The OA progression also showed no significant difference between the two groups. After a 10-year follow-up, the survival rate was higher in UKA patients (96.2%) than in OWHTO patients (87.7%), with no statistical difference (P = .06). CONCLUSION: UKA showed better clinical outcomes and OA progressions than OWHTO. The survival rate presented a superiority of 8.5% for the UKA group in the 10-year follow-up, without significant difference.

Brachymetacarpia and Brachymetatarsia in Patients with Multiple Hereditary Exostosis.

BACKGROUND: Multiple hereditary exostosis is a common autosomal dominant inherited musculoskeletal disorder that manifests with multiple osteochondromas. The clinical manifestations and pathological characteristics of osteochondromas found in the long bone and genetic alterations related to multiple hereditary exostosis have been widely reported. In this study, we investigated the characteristics of brachymetacarpia and brachymetatarsia associated with multiple hereditary exostosis. METHODS: Of the 133 patients with a diagnosis of multiple hereditary exostosis who were recruited from 2005 to 2018, 101 patients who underwent plain radiography after 10 years of age were included. There were 55 male (54.5%) and 46 female (45.5%) patients. Brachymetacarpia or brachymetatarsia was diagnosed when disruption of the Lièvre parabola connecting the metacarpal or metatarsal heads was observed on plain radiographs. Three orthopedic surgeons individually reviewed hand and foot plain radiographs. RESULTS: Of the 101 patients, 41 patients (40.6%) had more than 1 brachymetacarpia (88 cases) or brachymetatarsia (81 cases). Among 41 cases, 22 (53.7%) were male and 19 (46.3%) were female. The mean age at the time of radiographic evaluation of the hands and feet was 14.6 years (range, 10-63 years). Shortening was most commonly found in the 3rd and 4th metacarpal or metatarsal bones. CONCLUSIONS: We found a relatively high incidence of brachymetacarpia and brachymetatarsia in our patients. Physicians should suspect the presence of brachymetacarpia and brachymetatarsia when treating patients with multiple hereditary exostosis.

No difference in the anteroposterior stability between the GRADIUS and multi-radius designs in total knee arthroplasty.

BACKGROUND: This retrospective study aimed to compare stability and clinical and radiological outcomes of total knee arthroplasty (TKA) for the GRADIUS and multi-radius femoral designs after minimum of two-year follow-up. METHODS: A total of 142 patients who underwent TKA using ATTUNE posterior stabilized (PS) implants (68 patients, GRADIUS group) or Persona PS implants (74 patients, multi-radius group) for degenerative osteoarthritis were included. After an average of 2-year follow-up, the anteroposterior (AP) stability at 30°, 60°, and 90° was measured using KT 2000 device and compared between the two groups. The clinical outcome measurements included range of motion (ROM) of the knee, patient-reported outcomes and anterior knee pain (AKP). For the clinical evaluation of mid-flexion instability, pain was evaluated using the visual analog scale (VAS) score recorded during climbing up or going down stairs. The radiolucent lines on knee radiographs obtained at final follow-up were evaluated and compared between two groups. RESULTS: The average AP stability at 30° knee flexion was 5.7 mm in the GRADIUS group and 5.9 mm in the multi-radius group; however, the difference was not significant. The AP stability at 60° and 90° knee flexion was also similar in both groups. There were no significant differences in the ROM, patient-reported outcomes at follow-up, incidence of AKP and VAS scores between the two groups. There were no differences in the incidence of radiolucency around the components between the two groups. CONCLUSION: The GRADIUS design did not show any advantage with respect to the stability or clinical outcomes compared with the multi-radius design in TKA.

Comparison of Posterior Cruciate-Retaining and High-Flexion Cruciate-Retaining Total Knee Arthroplasty Design.

BACKGROUND: High-flexion prostheses have been developed to achieve deep flexion after total knee arthroplasty. The purpose of this study is to compare standard NexGen (CR, cruciate-retaining) and high-flexion NexGen (CR-flex) total knee prostheses in terms of range of motion, clinical and radiologic outcomes, rates of complications, and survivorship in long-term follow-up. METHODS: From January 2000 to December 2008, 423 consecutive knees underwent total knee arthroplasty using standard CR or CR-flex prostheses. Fifty-three patients were lost to follow-up or declined to participate and 54 died, leaving 290 knees. The minimum duration of follow-up was 8 years (mean 10.1 years). Physical examination and knee scoring of patients were assessed preoperatively, at 6 months and 1 year after surgery, and annually thereafter. Supine anteroposterior and lateral radiographs and standing anteroposterior hip-to-ankle radiographs were obtained preoperatively and at each follow-up. RESULTS: Mean postoperative range of motions in the standard CR group and the CR-flex group were similar, showing no significant difference between the 2 groups (P = .853). At the time of the final follow-up, mean total Hospital for Special Surgery scores were similar between the 2 groups (P = .118). Mean Knee Society pain (P = .325) and function scores (P = .659) were also comparable between the 2 groups. Western Ontario and McMaster Universities Osteoarthritis Index score showed no intergroup difference either (P = .586). The mean hip-knee-ankle angle at the final follow-up was approximately the same (P = .940). Mean coronal angles of femoral and tibial component at final follow-up were also similar (P = .211 and P = .764, respectively). The prevalence of the radiolucent line was 0.6% in the standard CR group and 0.9% in the CR-flex group. Estimated survival rate according to Kaplan-Meier survival analysis was 97.2% in the standard CR group and 95.6% in the CR-flex group at mean follow-up of 10.1 years. CONCLUSION: This study suggests that excellent clinical and radiographic outcomes could be achieved with both standard and high-flexion CR total knee designs. High-flexion CR prosthesis did not show any advantages over the standard design.

A Comparative Study Between Patient-Specific Instrumentation and Conventional Technique in TKA.

Patient-specific instrumentation (PSI) was developed to improve the accuracy of component positioning through custom cutting blocks constructed based on preoperative 3-dimensional imaging in total knee arthroplasty (TKA). The purpose of this study was to compare the clinical and radiological outcomes between the patients who underwent PSI-assisted TKA or conventional TKA. Sixty-four patients (64 knees) underwent TKA by a single surgeon: 32 patients (32 knees) underwent TKA with PSI, 32 patients (32 knees) underwent TKA with conventional instrumentation. The mean age of the patients was 67.6 years, and the mean follow-up duration is 26.2 months. Patients were evaluated preoperatively and after surgery. The current authors evaluated clinical outcomes including knee range of motion, Hospital for Special Survey scale, Western Ontario and McMaster University Osteoarthritis Index, and Knee Society pain and function scores. The current authors also compared radiological outcomes including mechanical axis and coronal and sagittal alignment. The current authors found no significant differences in any clinical outcomes between the PSI-assisted TKA group and the conventional TKA group. In terms of radiological outcomes, the PSI-assisted TKA group had fewer alignment outliers. The current authors found that PSI-assisted TKA restores limb alignment better than conventional TKA, but PSI does not confer a substantial advantage in early functional outcomes after TKA. Further follow-up is needed to ascertain the long-term impact of these findings. [Orthopedics. 2016; 39(3):S83-S87.].

Vertebral compression fracture within a solid fusion mass without trauma after removal of pedicle screws.

BACKGROUND CONTEXT: Many complications of lumbar fusion have been reported. However, reports of complications related to implant removal after solid fusion are rare. In addition, there are almost no reports of compression fractures occurring within a fusion mass. PURPOSE: This work aimed to report a case of vertebral body compression fracture within a solid lumbar fusion mass after removal of fusion instrumentation, and to investigate the contributing factors. STUDY DESIGN: A case report was carried out. METHODS: A 67-year-old woman presented with gait disturbance and pain radiating from both lower extremities. She had a history of lumbar fusion at L2-L5 because of degenerative stenosis. We found spinal stenosis at L5-S1 and ossification of the ligamentum flavum at T12-L2. Posterior decompression and fusion were performed for the lesion, and previously inserted fusion instrumentation was removed at L2-L5 in accordance with the patient's request. After surgery, her symptoms decreased and she was discharged. Five weeks after surgery, the patient returned with sudden, severe back pain that occurred without trauma. Compression fracture at the L3 lower end plate was observed via magnetic resonance imaging. We treated her back pain with analgesics and a thoracolumbosacral orthosis. After 2 weeks, her back pain had decreased, and she was discharged. RESULTS: Before removal of instrumentation, we verified complete union using computed tomography. However, an unexpected compression fracture occurred within the fusion mass, without trauma. We suspect that the causes of the compression fracture were the straight sagittal imbalance of the spine, the cantilever motion in the anterior disc after posterior fusion, and decreased bone strength. CONCLUSIONS: Vertebral compression fracture in a solid fusion mass may occur as a complication of implant removal. Surgeons must take care to maintain normal sagittal alignment during spinal fusion, and they should consider careful removal of instrumentation for patients with risk factors such as osteoporosis, sagittal imbalance, long spine fusion, and certain types of fusion.