Obesity is a risk factor for osteoarthritis progression and spontaneous osteoporosis is a risk for the development of spontaneous osteonecrosis in patients with medial meniscus posterior root tear.

BACKGROUND: Obesity is a representative risk factor for osteoarthritis (OA). The relationship between osteoporosis and executed osteonecrosis has been reported. The primary aim of this study was to determine the influence of obesity and osteoporosis on disease progression in patients with medial meniscus posterior root tear (MMPRT). METHODS: We included 41 knees with MMPRT in this study. MMPRT was diagnosed based on the presence of both a meniscus ghost sign and a vertical linear defect on MRI. OA progression and development of osteonecrosis were evaluated using plain radiographs obtained at the initial visit and the final follow-up. The follow-up period for all knees was 30 ± 8 (mean ± standard deviation) months. Patients' physical attributes were assessed at initial visits; these attributes included body mass index (BMI) and the clinical risk for osteoporotic fracture, as determined by the World Health Organization fracture risk assessment tool (FRAX). Patients with a BMI ≥25 kg/m2 were classified in the obesity group and those with a BMI <25 kg/m2 in the control group. Patients with a FRAX score of ≥10% were classified in the high FRAX group and those with a FRAX score of <10% in the low FRAX group. RESULTS: OA progression evaluated by Kellgren-Lawrence grading scale was observed in 75% patients in the obesity group (1 grade in 38%, 2 grades in 31%, and 3 grades in 6%) and 58% in the control group (1 grade in 58%). Patients in the obesity group showed significantly greater OA progression. Spontaneous osteonecrosis was observed in no knees at the initial visit and six knees at the final follow-up. All six lesions were observed in the high FRAX group, which was statistically significant. CONCLUSIONS: OA progression and development of osteonecrosis were the two representative deterioration patterns in patients with MMPRT. High BMI was related with OA progression, and FRAX score of ≥10% with the development of osteonecrosis.

Meniscal tear morphology independently affects pain relief following arthroscopic partial meniscectomy in middle-aged patients.

PURPOSE: To analyze the influence of meniscal tear pattern on clinical outcomes following arthroscopic partial meniscectomy in middle-aged patients with medial meniscal tears. METHODS: A total of 123 patients (130 knees) aged ≥ 50 years who underwent arthroscopic partial meniscectomy for medial meniscal tears were evaluated. Inclusion criteria were none to moderate medial knee osteoarthritis [Kellgren-Lawrence (KL) grade ≤ 3] and a minimum of 2-year follow-up (median 4.6 years; range 2.1-8.0 years). Meniscal tears observed during arthroscopic examination were classified into six types: radial tear of the middle segment, posterior root tear, horizontal tear of the posterior segment, flap tear, minor tear, and complex tear. Postoperative outcomes were classified into effective (group 1) and non-effective (group 2) according to the pain relief administered 1 month postoperatively and at the final follow-up. Demographic variables, KL grade, type of meniscal tear, and postoperative follow-up period were evaluated. RESULTS: Forty knees (38%) were classified into group 1. Of the six types of tears, radial tear of the middle segment [odds ratio (OR) 4.1, 95% confidence interval (CI) 1.1-20.9] and flap tear (OR 12.9, 95% CI 1.8-140.7) were significant predictors of good outcome on multivariate logistic regression analysis. CONCLUSIONS: In middle-aged patients with medial meniscal tears, radial tear of the middle segment was independently associated with less pain following arthroscopic meniscectomy. Arthroscopic partial meniscectomy may be indicated in patients with radial tear if conservative treatment fails. LEVEL OF EVIDENCE: Case-control study, Level III.

Closed Reduction of "Irreducible" Posterolateral Knee Dislocation - A Case Report.

INTRODUCTION: Posterolateral rotary knee dislocation is a rare orthopedic injury that is considered to be irreducible by closed reduction because of soft tissue incarceration. Here, we present a case of posterolateral rotary knee dislocation, which was reduced by closed manipulation. CASE REPORT: The patientwas a 33-year-old man who sustained a twisting injury to his right knee that was diagnosed as posterolateral rotary knee dislocation by plain radiographs and the characteristic physical finding known as a dimple sign. Under general anesthesia, the knee dislocation was reduced by closed manipulation with internal rotation of the lower leg at knee flexion and reproduced by valgus and external rotation stress. There were was complete tear of posterior cruciate ligament, and partial tear of the anterior cruciate ligament which were not reconstructed. The medial collateral ligament that was detached from the femoral footprint was repaired. One year postoperatively, the range of motion was 0-145°. There was no knee symptom and no ligament instability. CONCLUSION: This is the first report of a successful closed reduction for posterolateral knee dislocation. The mechanism of dislocation was considered valgus and external rotation stress during knee flexion.

Medial meniscus tear morphology and related clinical symptoms in patients with medial knee osteoarthritis.

PURPOSE: The objective of this study was to examine the association between clinical symptoms and arthroscopic meniscal findings in patients with early to moderate medial knee osteoarthritis. METHODS: One hundred and four patients (110 knees) were selected from a group of 132 patients (140 knees) aged ≥50 years who underwent arthroscopic surgery for medial meniscal tears. Inclusion criteria were as follows: (a) medial knee osteoarthritis and (b) simple medial meniscal tears extending to ≥1/4 of the meniscal margin. Subjective symptoms, location and nature of the pain, as well as the physical findings observed during initial assessment were evaluated using a standardized assessment chart. The relationship between arthroscopic meniscal findings and clinical symptoms was then analysed. RESULTS: Isolated meniscal tears were classified into four types: radial tear of the middle segment; posterior root tear; horizontal tear of the posterior segment; and flap tear. The following symptoms were reported at significantly higher frequencies: pain on standing and a catching sensation in patients with flap tears; pain on walking and nocturnal pain on rolling over in bed in patients with radial tears of the middle segment; and popliteal pain in patients with posterior root tears. CONCLUSIONS: This study demonstrates a relationship between the type of medial meniscal tear and characteristic clinical symptoms reported by patients with medial knee osteoarthritis. These results suggest that clinical symptoms in patients with osteoarthritis of the knee may be caused by meniscal tears. This evidence may help to better inform patients and surgeons regarding choice of treatment. LEVEL OF EVIDENCE: Case control study, Level III.

Comparison of cervical spinal canal diameter between younger and elder generations of Japanese.

BACKGROUND: Cervical myelopathy is more common among Japanese than Westerners. The shorter anteroposterior diameter of the cervical spinal canals (AP diameter) is its probable cause. In recent years, builds of younger Japanese have become larger and been approaching those of Westerners. The purpose of this study was to investigate whether the cervical spinal canal had enlarged in the younger Japanese as well as any cross-sectional improvement in their builds. METHODS: The subjects included 300 men and 300 women who were healthy and without symptoms related to the cervical spine. They were divided into six age groups at 10-year intervals from the twenties to the seventies. Height, body weight, and arm span were measured as physical factors. Using lateral dynamic radiographs of the cervical spine, the AP diameter from C3 to C6 in the neutral position and Penning's jaw diameter in extension (jaw diameter) from C2/3 to C5/6 were measured. The number of trapezoid-shaped vertebral bodies with a thickened posterior margin were also counted as such thickening might be one of the causes of spinal canal narrowing. Statistical analysis was performed for the following associations in both sexes: (1) age and physical factors; (2) age and the AP diameter; (3) age and jaw diameter; and (4) the difference of the AP diameter of the canal within and outside the trapezoid-shaped deformity of the vertebral body. RESULTS: In both men and women, the younger generations statistically had a larger height, arm span, and AP diameter. Older generations showed a significantly narrower jaw diameter at all measured spinal levels in both sexes. Trapezoid-shaped vertebral bodies were found in 3.5% of the men and in 1.3% of the women in their fifties, sixties, and seventies, which statistically had no effect on the AP diameter being wider in the younger generations. CONCLUSIONS: Younger generations had larger builds and a wider canal of the cervical spine. A narrow spinal canal is a fundamental risk factor for cervical myelopathy. Therefore, cervical myelopathy might be expected to decrease in Japan in the near future when the present younger generations have aged.

Crowned Dens syndrome.

BACKGROUND: Patients with crowned dens syndrome typically present with severe neck pain and have calcium deposits around the odontoid process of the axis on radiographs. To our knowledge, the cases of only thirty-five patients have been reported in the English-language literature and the clinical features remain unclear. The purposes of this study were to examine the clinical features of crowned dens syndrome, determine treatment outcomes, and propose diagnostic criteria. METHODS: Forty patients with severe neck pain had calcium deposition around the odontoid process on computed tomography scans, and they were thus diagnosed as having crowned dens syndrome. Data were collected in relation to these patients, including the date of onset of neck pain, the presence of inflammatory indicators (increased body temperature, C-reactive protein levels, and white blood-cell count), and treatment outcomes. RESULTS: The male-to-female ratio was 0.6, and two-thirds of the patients were more than seventy years of age. All patients had markedly restricted neck motion, particularly in rotation, and all had one or more positive inflammatory indicators. Calcium deposition was detected in all areas around the odontoid process, but chiefly behind the process. Pain was typically relieved by nonsteroidal anti-inflammatory drugs, prednisolone, or both. A combination of both appeared to be the most effective. CONCLUSIONS: We believe that crowned dens syndrome is more common than previously recognized, especially in elderly patients. It is diagnosed on the basis of acute and severe neck pain; marked restriction of neck motion, particularly in rotation; the presence of inflammatory indicators, such as an elevated C-reactive protein level; calcium deposition around the odontoid process detected by computed tomography; no history of trauma; and the exclusion of other inflammatory diseases and tumors. Prednisolone and nonsteroidal anti-inflammatory drugs in combination are the recommended treatment for symptom relief.

Pigmented villonodular synovitis of the knee with lesions of the bursae.

Five patients with pigmented villonodular synovitis of the knee associated with lesions of the posterior periarticular bursae were treated by posterior exploration, excision of the bursal tissue, and routine anterior synovectomy of the knee. It was hypothesized that complete excision of the posterior periarticular bursae would reduce the high recurrence rate of pigmented villonodular synovitis of the knee. To completely excise the periarticular lesions, two posterior oblique skin incisions were used. In all patients, periarticular lesions were seen clearly on computed tomography scans after air arthrography and on magnetic resonance imaging scans. The patients were followed up for 6.9 years on average (range, 3.3-8.1 years) after surgery. One of five patients required reoperation because of recurrence. Two of five patients required manual mobilization after release of the intraarticular adhesion. However, in the remaining three patients, who started continuous passive motion exercise immediately after surgery, full range of motion was restored within 3 months after the operation. Complete excision of the periarticular lesions is recommended to reduce the high recurrence rate, and continuous passive motion exercise immediately after surgery also is recommended to prevent reduction of range of motion.