Rebound of Frontal Plane Malalignment After Tension Band Plating.

BACKGROUND: Despite the popularity of tension band plating (TBP) current literature lacks clinical data concerning recurrence ("rebound") of frontal plane malalignment. This study investigated the rebound phenomenon after TBP in idiopathic genu varum/valgum deformities. We analyzed factors that may contribute to the development of rebound after removal of TBP. METHODS: Patients who had correction of idiopathic valgus or varus deformities by TBP at the distal femoral and/or proximal tibial growth plate were selected from a prospective consecutive database. Only patients who had plates removed for at least 1 year and had a long standing radiograph of the lower limbs before plate removal were included. Patients who had presumably not yet reached skeletal maturity (age under 14 y for girls and under 16 y for boys) were excluded. The change of the mechanical axis from plate removal to follow-up after skeletal maturity was evaluated and a statistical analysis was performed. RESULTS: Twenty-nine patients (64 extremities) were eligible. The mean follow-up was 39.1 months (range, 12.3 to 67.3 mo). The mean mechanical axis deviation (MAD) was +0.8 mm (range, -26 to +22 mm) after plate removal and -2.4 mm (range, -29 to +27 mm) at follow-up, accounting for a significant change of MAD (P=0.046). We observed a mean, relative recurrence of frontal plate malalignment into valgus direction of -3.2 mm (range, -48 to +23 mm). Twenty extremities (31%) showed <3 mm of MAD change; 27 extremities (42%) showed >3 mm of MAD change into valgus, and 17 extremities (27%) >3 mm of MAD change into varus direction. Patients with <3 mm MAD change had only 0.8 years, and those >3 mm a mean of 2.0 years of remaining growth until skeletal maturity. Each additional m/kg of body mass index increased the risk of valgus recurrence by 12.1%. The 3 genua vara patients revealed to have an even higher rate of malalignment recurrence (4 of 6 limbs) at final follow-up. CONCLUSIONS: Given our strict criteria, there is a high rate of radiologic recurrence of frontal plane malalignment after TBP. Children who are more than 1 year before skeletal maturity at TBP removal, and those with increased body mass index are at higher risk for rebound growth. LEVEL OF EVIDENCE: Level IV-consecutive therapeutic case series.

Natural course of intra-articular shifting bone marrow edema syndrome of the knee.

BACKGROUND: Intra-articular shift (migration) of bone marrow edema syndrome (BMES) is a very rare disease. Only a few cases have been reported thus far. The condition may cause the clinician to suspect an aggressive disease. METHODS: We reviewed eight patients (four women and four men) with unilateral BMES located in the knee. The patients were aged 39 to 56 years (mean, 49.2 years). In all patients, bone marrow edema (BME) initially observed on magnetic resonance imaging (MR imaging) shifted within the same joint, i.e. from the medial to the lateral femoral condyle or the adjacent bone. Seven patients were given conservative therapy, including limited weight-bearing, for a period of three weeks after the initial detection of BMES, whereas one patient underwent surgical core decompression twice. RESULTS: MR imaging showed complete restitution in 6 cases and a small residual edema in one case. A final control MR could not be obtained for one patient, who had no pain. A further patient had an avascular necrosis of the contralateral hip after 16 months. Improvement on MR imaging was correlated with the clinical outcome in all cases. All patients became asymptomatic after a mean period of 9 months (6-11). INTERPRETATION: Intra-articular shifting BMES is a very rare condition. As the disease is self-limiting, conservative therapy may be recommended.

Outcome of painful bone marrow edema of the femoral head following treatment with parenteral iloprost.

BACKGROUND: Bone marrow edema (BME) is a common cause of hip pain. The aim of the study was to assess the efficacy of the vasoactive drug iloprost in the treatment of BME of femoral head. MATERIALS AND METHODS: We reviewed 27 patients (19 male, 8 female) with BME of the femoral head. Their mean age was 53.7 +/- 10.8 years. All patients were treated with iloprost, a vasoactive drug that dilates arterioles and venules, reduces capillary permeability and suppresses platelet aggregation. The therapy comprised a series of five infusions with 20 to 50 mug iloprost over 6 h on 5 consecutive days each. Weight bearing was reduced for up to 3 weeks, depending on the severity of symptoms. Pain at rest as well as under stress was assessed with a semi quantitative scale from before and 4 months after therapy. MRI investigations were done before and repeated 4 months after therapy. RESULTS: At the clinical follow up of four months after therapy, the pain level at rest had diminished by a mean of 58.3% (P < 0.0001). Pain under stress decreased by a mean of 41.9% (P < 0.0001). On MRI, 20 patients had a significant reduction of BME size or complete normalization and 4 showed no change. Worsening of the MRI pattern was found in 3 patients. CONCLUSION: The authors conclude that the use of parenteral iloprost might be a viable method in the treatment of BME of femoral head.