Association of Mechanical Axis With Osteochondritis Dissecans of the Femoral Condyle.

BACKGROUND: Osteochondritis dissecans (OCD) is a condition characterized by abnormal subchondral bone with disturbance of overlying articular cartilage. The role of weightbearing alignment in the pathophysiology of OCD lesion development is not fully understood. HYPOTHESIS: Lower extremity mechanical axis would be concordant with femoral condylar OCD lesion location. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Cases were identified from a single, large academic institutional database using International Classification of Diseases, Ninth Revision and Tenth Revision and Current Procedural Terminology codes associated with OCD. Patients were included if they had a magnetic resonance imaging scan demonstrating the OCD lesion and lower extremity alignment radiographs. OCD lesion location was identified using Cahill and Berg zones. The primary outcome was the association of OCD lesion location with weightbearing mechanical axis. Secondary outcomes included the association of mechanical axis with skeletal maturity, OCD lesion stability, and treatment. For unilateral OCD lesions, mechanical axis was compared between affected and unaffected lower extremities. RESULTS: A total of 86 patients (95 knees) with an OCD lesion of the femoral condyle were identified. The population was 74% male, and the mean age was 21 years. In total, 65% of knees had closed physes, 82% of lesions were unstable, and 85% underwent a surgical procedure. Mechanical axis was located in the same zone as the OCD lesion in 48% of cases and within the same compartment in 56% of cases. Spearman correlation coefficient demonstrated a moderate positive correlation (rs = 0.59). No significant differences were found in the association of mechanical axis and OCD lesion location in subgroup analysis of medial versus lateral femoral condylar OCD lesions, skeletal maturity, stability of the lesion, or treatment group. For patients with varus alignment and medial femoral condylar OCD lesions, the mean lateral distal femoral angle was 89.9°, and medial proximal tibial angle was 85.4°; for valgus alignment and lateral femoral condylar lesions, the lateral distal femoral angle was 84.8°, and medial proximal tibial angle was 88.8°. Patients with unilateral medial femoral condylar OCD lesions were more likely to have varus alignment of the affected extremity compared with the contralateral extremity (59% vs 36%; P = .01). CONCLUSION: This study demonstrated a relationship between lower extremity mechanical weightbearing axis and femoral condylar OCD location. Patients with unilateral medial femoral condylar OCD lesions frequently had asymmetric varus alignment in the affected extremity.

Subchondral Bone Alignment in Osteochondral Allograft Transplants for Large Oval Defects of the Medial Femoral Condyle: Comparison of Lateral versus Medial Femoral Condyle Donors.

OBJECTIVE: Supply-demand mismatch of medial femoral condyle (MFC) osteochondral allografts (OCAs) remains a rate-limiting factor in the treatment of osteochondral defects of the femoral condyle. Surface contour mapping was used to determine whether a contralateral lateral femoral condyle (LFC) versus ipsilateral MFC OCA differs in the alignment of donor:native subchondral bone for large osteochondral defects of the MFC. DESIGN: Thirty fresh-frozen human femoral condyles were matched by tibial width into 10 groups of 3 condyles (MFC recipient, MFC donor, and LFC donor) each for 3 cartilage surgeons (90 condyles). The recipient MFC was imaged using nano-computed tomography scan. Donor oval grafts were harvested from each matched condyle and transplanted into a 17 mm × 36 mm defect created in the recipient condyle. Following the first transplant, the recipient condyle was imaged and superimposed on the native condyle nano-CT scan. The donor plug was removed and the process repeated for the other donor. Surface height deviation and circumferential step-off height deviation were compared between native and donor subchondral bone surfaces for each transplant. RESULTS: There was no statistically significant difference in mean subchondral bone surface deviation (LFC = 0.87 mm, MFC = 0.76 mm, P = 0.07) nor circumferential step-off height (LFC = 0.93 mm, MFC = 0.85 mm, P = 0.09) between the LFC and MFC plugs. There were no significant differences in outcomes between surgeons. CONCLUSIONS: There were no significant differences in subchondral bone circumferential step-off or surface deviation between ipsilateral MFC and contralateral LFC oval-shaped OCAs for 17 mm × 36 mm defects of the MFC.

Characterization of Micro-Threaded Stem Taper Surfaces of Cementless Hip Endoprostheses.

We investigated micro-threaded stem taper surface and its impact on premature failures, aseptic loosening, and infection in cementless hip endoprostheses. Our study focused on the fretting, and crevice corrosion of micro-threaded tapers, as well as the characterization of the microstructure and surface properties of two new and three retrieved Zweymüller stem tapers. The retrieved samples were selected and examined based on the head-stem taper interface being the sole source of modularity with a metallic component, specifically between the Ti alloy taper stem and the ceramic head. To determine the surface chemistry and microstructures of both new and retrieved hip endoprostheses stem taper titanium alloy, scanning -electron microscopy (SEM) was employed for morphological and microstructural analyses. Energy dispersive spectroscopy (EDS) was utilized for characterizing chemical element distribution, and electron backscattered diffraction (EBSD) was used for phase analysis. The roughness of the micro-threated stem tapers from different manufacturers was investigated using an optical profilometer, with standard roughness parameters Ra (average surface roughness) and Rz (mean peak to valley height of the roughness profile) being measured. Electrochemical studies revealed no fretting corrosion in retrieved stem tapers with ceramic heads. Consequently, three retrieved tapers and two new ones for comparison underwent potentiodynamic measurements in Hank's solution to determine the corrosion rate of new and retrieved stem taper surfaces. The results showed a low corrosion rate for both new and prematurely failed retrieved samples due to aseptic loosening. However, the corrosion rate was higher in infected and low-grade infected tapers. In conclusion, our study suggests that using ceramic heads reduces taper corrosion and subsequently decreases the incidence of premature failures in total hip arthroplasty.

Arthroscopy Association of Canada Position Statement on Opioid Prescription After Arthroscopic Surgery.

Background: Despite the ongoing opioid epidemic, most patients are still prescribed a significant number of opioid medications for pain management after arthroscopic surgery. There is a need for consensus among orthopaedic surgeons and solutions to aid providers in analgesic strategies that reduce the use of opioid pain medications. Purpose: This position statement was developed with a comprehensive systematic review and meta-analysis of exclusively randomized controlled trials (RCTs) to synthesize the best available evidence for managing acute postoperative pain after arthroscopic surgery. Study Design: Position statement. Methods: The Embase, MEDLINE, PubMed, Scopus, and Web of Science databases were searched from inception until August 10, 2022. Keywords included arthroscopy, opioids, analgesia, and pain, and associated variations. We included exclusively RCTs on adult patients to gather the best available evidence for managing acute postoperative pain after arthroscopic surgery. Patient characteristics, pain, and opioid data were extracted, data were analyzed, and trial bias was evaluated. Results: A total of 21 RCTs were identified related to the prescription of opioid-sparing pain medication after arthroscopic surgery. The following recommendations regarding noninvasive, postoperative pain management strategies were made: (1) multimodal oral nonopioid analgesic regimens-including at least 1 of acetaminophen-a nonsteroidal anti-inflammatory drug-can significantly reduce opioid consumption with no change in pain scores; (2) cryotherapy is likely to help with pain management, although the evidence on the optimal method of application (continuous-flow vs ice pack application) is unclear; (3) and (4) limited RCT evidence supports the efficacy of transcutaneous electrical nerve stimulation and relaxation exercises in reducing opioid consumption after arthroscopy; and (5) limited RCT evidence exists against the efficacy of transdermal lidocaine patches in reducing opioid consumption. Conclusion: A range of nonopioid strategies exist that can reduce postarthroscopic procedural opioid consumption with equivalent vocal pain outcomes. Optimal strategies include multimodal analgesia with education and restricted/reduced opioid prescription.