Tissue Integration of Calcium Phosphate Compound after Subchondroplasty: 4-Year Follow-Up in a 76-Year-Old Female Patient.

Subchondroplasty is a new minimally invasive surgical technique developed to treat bone marrow lesions (BML) and early osteoarthritis (OA). During the procedure, engineered calcium phosphate compound (CPC) is injected. It is claimed by the manufacturer that during the healing process, the CPC is replaced with new bone. The purpose of this study was to verify the replacement of CPC with new bone after subchondroplasty for the first time in humans. A 76-year old woman was referred for resistant medial knee pain. Standing radiographs showed varus knee OA and magnetic resonance imaging (MRI) revealed BML. She was treated with subchondroplasty of medial femoral condyle. Excellent relief of pain was achieved after procedure. Afterwards, the pain worsened, the radiographs confirmed the OA progression and the patient was treated with a total knee arthroplasty (TKA) 4 years after primary procedure. The resected bone was examined histologically and with micro-computed tomography (CT). Histologically, bone trabeculae of subcortical bone were embedded in the amorphous mass. However, no signs of CPC resorption and/or bone replacement have been found with micro-CT. In short term, excellent pain relief could be expected after the subchondroplasty procedure. However, there was no replacement of CPC with bone and the technique probably did not influence the natural process of knee OA.

Failure to maintain segmental lordosis during TLIF for one-level degenerative spondylolisthesis negatively affects clinical outcome 5 years postoperatively: a prospective cohort of 57 patients.

PURPOSE: The present study aimed to determine whether obtaining adequate lumbar (LL) or segmental (SL) lordosis during instrumented TLIF for one-level degenerative spondylolisthesis affects midterm clinical outcome. METHODS: The study was designed as a prospective one, including 57 patients who underwent single-level TLIF surgery for degenerative spondylolisthesis. Patients were analyzed globally with additional subgroup analysis according to pelvic incidence (PI). Radiographic analysis of spinopelvic sagittal parameters was conducted pre- and postoperatively. Clinical examination including ODI score was performed preoperatively, 1 and 5 years postoperatively. RESULTS: Significant improvement in ODI scores at 1 and 5 years postoperatively (p < 0.001) was demonstrated. There was a significant correlation between anterior shift of SVA and failure to improve SL (p = 0.046). Moreover, anterior SVA shift correlated with increased values of ODI score both 1 and 5 years postoperatively. In low-PI group, failure to correct LL correlated with high ODI scores 5 years postoperatively (r = - 0.499, p = 0.005). CONCLUSIONS: Failure to correct segmental lordosis during surgery for one-level degenerative spondylolisthesis resulted in anterior displacement of the center of gravity, which in turn correlated with unfavorable clinical outcome 1 and 5 years postoperatively. In patients with low PI, failure to maintain lumbar lordosis correlated with unfavorable clinical outcome 5 years after surgery. LEVEL OF EVIDENCE: II. These slides can be retrieved under Electronic Supplementary Material.