Tomoya Iseki

Analysis of risk factors for poor prognosis in conservatively managed early-stage spontaneous osteonecrosis of the knee

BACKGROUND Management guidelines for early-stage spontaneous osteonecrosis of the knee (SONK) have not been established. The purposes of this study were to review the outcome of conservative treatment for patients with early-stage SONK and to examine clinical factors affecting the prognosis. METHODS Diagnosis of early-stage SONK was made based on the criteria consisting of specific clinical features including magnetic resonance imaging (MRI) findings. During the study period, all patients with this diagnosis underwent standardized conservative treatment. The study population comprised 38 knees in 36 patients with a mean age at presentation of 66.4years. The mean follow-up period was 34.9months. During the treatment course, progressive joint space narrowing or collapse of bony contours identified in serial follow-up radiographs was regarded as indicating a poor prognosis. The significance of potential prognostic factors such as age, gender, obesity, coronal alignment, lesion size, and MRI findings was analyzed using a multivariate logistic regression analysis. RESULTS The prognosis was defined to be poor in eight knees (21.1%). The multivariate logistic regression analysis for potential risk factors revealed that only varus alignment with a femorotibial angle (FTA) of 180° or more on the initial radiograph was significantly associated with the poor prognosis (P=0.01, odds ratio 28.1) while no other factors significantly correlated with the prognosis. CONCLUSIONS Approximately 80% of patients with early-stage SONK could be managed successfully with conservative treatment without progression of the disease process. The presence of varus deformity (FTA of 180° or more) was significantly associated with poor prognosis complicated with progressive deformity and prolonged disability. LEVEL OF EVIDENCE Level IV, case series.

Double-bundle anterior cruciate ligament reconstruction with and without remnant preservation — Comparison of early postoperative outcomes and complications

BACKGROUND To compare the early postoperative outcomes and complications of double-bundle anterior cruciate ligament (ACL) reconstruction with and without remnant preservation. METHODS The study population comprised 125 consecutive knees that underwent double-bundle ACL reconstruction using hamstring autograft. Among the 125 knees, remnant preservation was indicated for 50 knees, while standard double-bundle reconstruction was performed in the remaining 75 knees. Postoperative evaluations included heel-height difference (HHD) at periodical follow-ups, number of knees requiring arthroscopic debridement due to problematic extension loss within six months, re-injury within one year, graft status upon second-look arthroscopy, and clinical examinations by Lysholm score and KT measurement at one year. RESULTS All patients could be followed up for a minimum of one year after surgery. When the results obtained from both groups were compared, HHD values were significantly larger in the preservation group at three and six months, and the rate of knees requiring arthroscopic debridement was also higher in this group (12% versus 4.0%). Graft status on second-look arthroscopy was considered to be good for 92% of the knees in the preservation group versus 59% in the non-preservation group. Re-injury rates within one year were 2.0% in the preservation group and 5.3% in the non-preservation group. No significant differences in clinical examinations were found between the groups at one year. CONCLUSIONS Remnant preservation in double-bundle hamstring autograft ACL reconstruction may enhance tissue healing; however, retention of the remnant with its full volume resulted in an increased incidence of postoperative problematic extension loss.

Comparison of transportal and outside-in techniques for posterolateral femoral tunnel drilling in double-bundle ACL reconstruction -three-dimensional CT analysis of bone tunnel geometry

PURPOSE To comparatively analyze the geometry of the posterolateral femoral (PL) tunnel in double-bundle ACL reconstruction between far anteromedial transportal (TP) and outside-in (OI) drilling techniques based on three-dimensional computed tomography (3DCT) image analysis. METHODS Forty patients who underwent anatomic double-bundle hamstring ACL reconstruction using the TP (n: 20) or OI (n: 20) method with postoperative CT data available were included in the study. The analyzed parameters were as follows: location of the intraarticular tunnel aperture, tunnel length, bending angle (angulation of the graft at the intraarticular tunnel aperture), and long axis of the tunnel aperture/drill diameter ratio as a parameter of ellipsoidal geometry. RESULTS Anatomical tunnel placement was achieved in both groups. Coalition of the AM and PL tunnel apertures was found in 3 knees in the TP group and 1 knee in the OI group, though no significant difference in the rate of this problem was demonstrated between the groups (P: 0.30). The tunnel length was not significantly different between the groups, while the graft bending angle at the tunnel aperture was significantly larger in the OI group than the TP group (99.4° vs. 63.6°). The long axis/drill diameter ratio averaged 1.23 in the TP group and 1.13 in the OI group with significant intergroup difference. CONCLUSION When drilling the PL femoral tunnel in double-bundle ACL reconstruction, anatomic placement of the intraarticular tunnel aperture was feasible in both the TP and OI techniques. The tunnel aperture was rounder and the graft bending angle in knee extended position at the intraarticular aperture was more acute in the OI technique than the TP technique. LEVEL OF EVIDENCE Level IV (retrospective comparison of the two patient groups treated at different hospitals).

Analysis of risk factors for poor prognosis in conservatively managed juvenile osteochondritis dissecans of the lateral femoral condyle

BACKGROUND The purpose of this study was to examine factors affecting the prognosis of conservative treatment for stable juvenile osteochondritis dissecans (OCD) of the lateral femoral condyle based on review of our patient population. METHODS A consecutive series of 43 knees in 37 patients with stable OCD of the lateral femoral condyle with open physes undergoing conservative treatment were included in the study. The mean age of the included subjects was 10.7±2.5years (range, seven to 16years) with the mean follow-up period of 33.3±15.1months (range, 12 to 67months). Conservative treatment consisting of prohibition of sports activities and use of a brace locking the knee in full extension was applied to all included patients. Potential prognostic factors examined were the presence of discoid meniscus, radiographic stage, lesion size on radiographs, time period from onset of symptoms to evaluation/consultation, number of hours of sporting activity per week, and age at starting sports activities. Prognosis of a patient was deemed to be poor when an apparent healing response was not detected in follow-up radiographic studies within six months. RESULTS The prognosis was defined to be poor for 14 knees (32.6%). The presence of discoid meniscus was identified in 100% of the knees in the poor prognosis group and time-period from onset to consultation of six months or more was shown to be a risk factor with statistical significance. CONCLUSIONS A majority of patients with juvenile OCD in the lateral femoral condyle could be managed with conservative treatment. The presence of discoid meniscus and longer time-period from onset to consultation were significantly related with poor prognosis. LEVEL OF EVIDENCE IV (case series).

Juvenile osteochondritis dissecans in the lateral femoral condyle requiring osteochondral autograft as a revision procedure: a case report

BackgroundThe optimal treatment option for osteochondritis dissecans of the knee is still controversial. We report the case of a boy who developed osteochondritis dissecans in the lateral femoral condyles of his bilateral knees requiring repeat surgical procedures. There has been no literature reporting juvenile osteochondritis dissecans of bilateral knees requiring repeat surgical procedures.Case presentationA 6-year-old Japanese boy presented with pain in his bilateral knees. Although conservative treatment with prohibition of sports activities was continued for 6 months, healing could not be attained. Conservative treatment consisting of prohibition of sports activities that included running and jumping and use of a brace with a locking mechanism at full extension was applied. He was instructed to walk with the brace. Since his lateral femoral osteochondritis dissecans lesion was located at the contact area during flexion, weight bearing with the use of the brace could effectively unload the lesion. Surgery was subsequently conducted on his left knee which had a more advanced stage lesion. Transchondral drilling was performed because the articular surface maintained its smooth continuity. At 9 months after the surgery, no appreciable healing was observed in the follow-up radiographs. Moreover, during the postoperative time course, lesions suggestive of osteochondritis dissecans in his contralateral right knee had become more evident. Based on the diagnosis of delayed union of bilateral osteochondritis dissecans lesions, a second surgery was attempted. The preceding arthroscopic observation of his left knee showed preserved surface continuity with softening and suspected partial detachment. Considering the delayed healing process observed in this patient, autogenous cylindrical osteochondral graft transplantation (8 mm in diameter) was performed as a revision procedure, while transchondral drilling was performed for the stable osteochondritis dissecans lesion in his right knee. Postoperatively, healing was achieved at 6 months.ConclusionsFollowing failed conservative treatment, he underwent arthroscopic drilling; however, the osteochondritis dissecans lesion did not heal requiring revision surgery using a cylindrical autogenous osteochondral graft. Finally, clinical and radiological healing was attained 6 months after the second surgery. Initial presentation at a young age with bilateral lesions may be clinical factors related to poor healing response and susceptibility to stress-related subchondral lesions.