Does Degeneration of the Patellofemoral Joint After Medial Open-Wedge High Tibial Osteotomy Affect Clinical Outcomes?

BACKGROUND: Although biomechanical and clinical studies have reported adverse effects on the patellofemoral joint after medial open-wedge high tibial osteotomy (MOWHTO), there is a paucity of literature that describes outcomes longer than midterm follow-up. PURPOSE: We aimed to evaluate the mid- to long-term radiologic and clinical outcomes of the patellofemoral joint after MOWHTO and to assess whether radiologic deterioration of the patellofemoral joint affected clinical outcomes or survivorship after MOWHTO. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We retrospectively reviewed 170 knees that underwent MOWHTO and had a minimum 5-year follow-up. In radiologic evaluation, serial postoperative changes in the patellofemoral joint compared with the preoperative status were evaluated on the Merchant view according to the Kellgren-Lawrence grade. The American Knee Society (AKS) score, Knee injury and Osteoarthritis Outcome Score (KOOS), Kujala score, incidence of anterior knee pain, and survivorship were used to assess clinical outcomes. Using radiologic assessment of the patellofemoral joint, we divided the patients into a radiologic progression group and a radiologic nonprogression group to evaluate whether radiologic progression of patellofemoral arthritis affected long-term clinical outcomes and survivorship after MOWHTO. RESULTS: The mean follow-up period was 96.3 months (range, 60-163 months). Arthritic progression of the patellofemoral joint on the Merchant view was observed in 44.9%, 56.3%, 66.0%, and 84.0% of the cases at 5, 7, 9, and 11 years, respectively. Clinical outcomes such as AKS scores and KOOS significantly improved after MOWHTO (P < .001) at the latest follow-up. The incidence of anterior knee pain was 5.3% (9/170 knees). One knee (0.6%) underwent conversion to TKA due to progressive medial osteoarthritis, so the survival rate was 99.4% at a mean follow-up of 96.3 months. Despite patellofemoral degeneration over time, there were no significant differences in clinical outcomes or survivorship between patients with and without radiologic progression at the latest follow-up. CONCLUSION: Although degeneration of the patellofemoral joint was observed with time after MOWHTO, the related symptoms were minimal and arthritic changes in the patellofemoral joint did not affect the clinical outcomes or survivorship after MOWHTO over a mid- to long-term follow-up.

Intra-articular Injection of Mesenchymal Stem Cells After High Tibial Osteotomy in Osteoarthritic Knee: Two-Year Follow-up of Randomized Control Trial.

Intra-articular injection of adipose-derived mesenchymal stem cell (ADMSC) after medial open-wedge high tibial osteotomy (MOWHTO) would be a promising disease-modifying treatment by correcting biomechanical and biochemical environment for arthritic knee with varus malalignment. However, there is a paucity of clinical evidence of the treatment. This randomized controlled trial (RCT) was aimed to assess regeneration of cartilage defect, functional improvement, and safety of intra-articular injection of ADMSCs after MOWHTO compared with MOWHTO alone for osteoarthritic knee with varus malalignment. This RCT allocated 26 patients into the MOWHTO with ADMSC-injection group (n = 13) and control (MOWHTO-alone) group (n = 13). The primary outcome was the serial changes of cartilage defect on periodic magnetic resonance imaging (MRI) evaluation using valid measurements until postoperative 24 months. Secondary outcomes were the 2-stage arthroscopic evaluation for macroscopic cartilage status and the postoperative functional improvements of patient-reported outcome measures until the latest follow-up. Furthermore, safety profiles after the treatment were evaluated. Cartilage regeneration on serial MRIs showed significantly better in the ADMSC group than in the control group. The arthroscopic assessment revealed that total cartilage regeneration was significantly better in the ADMSC group. Although it was not significant, functional improvements after the treatment showed a tendency to be greater in the ADMSC group than in the control group from 18 months after the treatment. No treatment-related adverse events, serious adverse events, and postoperative complications occurred in all cases. Concomitant intra-articular injection of ADMSCs with MOWHTO had advantages over MOWHTO alone in terms of cartilage regeneration with safety at 2-year follow-up, suggesting potential disease-modifying treatment for knee OA with varus malalignment.

Extra-articular Lateral Hinge Fracture Does Not Affect the Outcomes in Medial Open-Wedge High Tibial Osteotomy Using a Locked Plate System.

PURPOSE: To compare the radiologic and clinical outcomes in patients with and without lateral hinge fractures (LHFs) during medial open-wedge high tibial osteotomy (MOWHTO) using a locked plate system, as well as to assess whether LHFs could affect the midterm outcomes. METHODS: From May 2008 to November 2015, 164 knees underwent MOWHTO using a locked plate system for the treatment of knee osteoarthritis. LHFs were recognized by radiographs during or after the high tibial osteotomy and were not additionally treated. In all patients, we applied the same rehabilitation protocol that allowed full weight bearing at 6 weeks. Patients were divided into LHF (types I and II) and nonfracture groups. Radiologically, we compared any serial changes in the hip-knee-ankle angle, femorotibial angle, medial proximal tibial angle, and posterior tibial slope angle from the immediate postoperative radiographs to the final radiographs. The union process of the osteotomy site among the groups was also evaluated. Clinically, the postoperative American Knee Society Score and knee range of motion at latest follow-up were compared. Postoperative complications were also evaluated. RESULTS: The average age at operation was 56.0 years (range, 42-67 years), and the average follow-up period was 62.2 months (range, 24-120 months). LHFs were observed in 37 knees (22.6%) and were divided into the type I (16 knees) and type II (21 knees) groups. All groups showed no significant changes in serial evaluations of the postoperative hip-knee-ankle angle, femorotibial angle, medial proximal tibial angle, and posterior tibial slope angle. The improvements in the American Knee Society Score and knee range of motion were not significantly different among the groups. No patients showed correction loss or union problems. CONCLUSIONS: Type I and II LHFs in MOWHTO using a medial locked plate system and relatively conservative rehabilitation protocol with full weight-bearing walking commenced at 6 weeks postoperatively showed no radiologic changes or functional deterioration during midterm follow-up. LEVEL OF EVIDENCE: Level IV, case series.

Effect of ligamentum teres tear on the development of joint instability and articular cartilage damage: an in vivo rabbit study.

The contribution of the ligamentum teres to the stabilization of the hip joint and the clinical influence of a compromised ligamentum teres are not well known. This study aimed to investigate joint stability and cartilage damage in a rabbit model by surgically inducing a complete ligamentum teres tear. Twenty adult New Zealand rabbits were used in this study. Rabbits were divided into complete ligamentum teres tear with capsulotomy (n = 9, group I) and capsulotomy only (n = 10, group II) groups. Unilateral surgery was performed on the left hip. Joint instability was assessed by measuring the preoperative and postoperative acetabulofemoral (A-F) distances. Rabbits were euthanized to assess cartilage damage at 24 weeks postoperatively. The median postoperative A-F distance of the operated side in group I [0.68 cm (0.37-1.04 cm)] was larger than that in group II [0.50 cm (0.30-0.65 cm)] (p = 0.041). The median postoperative A-F distance was larger in the operated side [0.68 cm (0.37-1.04 cm)] compared to the nonoperated side [0.45 cm (0.30-0.75 cm)] in group I; it also was larger in the operated side [0.50 cm (0.30-0.65 cm)] compared to the nonoperated side [0.44 cm (0.32-0.67 cm)] in group II, but only group I showed a significant difference (p = 0.016 and 0.395, respectively). Articular cartilage damage was detected at the apex of the femoral head in two rabbits (22.2%) in group I only. Rabbits with a complete ligamentum teres tear showed significant instability at the hip joint and articular cartilage damage in our rabbit model, supporting the potential clinical importance of ligamentum teres as a hip joint stabilizer.

High incidence of early subtrochanteric lateral cortical atrophy after hip arthroplasty using bone-conserving short stem.

PURPOSE: Load transfer to the bone is believed to be more physiological around the short stem in total hip arthroplasty (THA). However, we found unusual bony remodeling around the shortened tapered stem. This study was performed to investigate the extent and frequency of this phenomenon and to find the possible risk factors of it. METHODS: Among 121 consecutive THA using the same short stem, 80 THAs were enrolled. Radiographic measurements were made using anteroposterior (AP) radiographs taken immediately and at two years after surgery. The thickness of the lateral cortex at the level of the distal end of the coated surface and at 10, 20, 30, and 40 mm proximal to it were measured. RESULTS: Significant atrophy was noted in all regions (P < 0.001 each). In 46 cases, this presented as an intra-cortical osteolytic line (IOL). Sixty-one cases showed either an IOL or atrophy >10%. The risk of a mean reduction >20% was related to an increased operating time (odds ratio [OR] = 0.981; 0.966 < 95% confidence interval [CI] < 0.996) and lower body mass index (BMI) (OR = 1.216; 1.043 < 95% CI < 1.417). Periprosthetic fracture through the lateral cortex occurred in one case. CONCLUSION: Even with THA using a shortened stem, high incidence of proximal stress shielding was noted in the form of lateral cortical atrophy, especially for the patient with low BMI.

The recovery of damaged paraspinal muscles by posterior surgical treatment for patients with lumbar degenerative diseases and its clinical consequence.

BACKGROUND: Posterior lumbar surgery can lead to damage on paraspinal muscles. OBJECTIVE: Our study aimed to examine the recovery in the denervated paraspinal muscles by posterior lumbar surgery and to determine that of improvement in the lower back pain (LBP). METHODS: Depending on surgical treatments, the patients were divided into two groups: The group I (interspinous implantation with decompression) and II (posterior lumbar interbody fusion with decompression). The paraspinal mapping score was recorded for individual muscle. RESULTS: In the group I, there was reinnervation in the denervated multifidus and erector spinae at the upper, surgical and lower levels at 12 months. In the group II, there was reinnervation in the denervated erector spinae at the upper, surgical and lower levels at 12 months. There was significant aggravation in the LBP in both groups at immediate postoperative. But there was significant improvement in it at 6 months in the group I and at 12 months in the group II. CONCLUSION: There was reinnervation in not only denervated multifidus and erector spinae at 12 months following interspinous ligament stabilization but also in denervated erector spinae at 12 months following pedicle screw fixation with fusion.