Spontaneous reduction in both dislocated head and dissociation of head-neck in a modular total hip arthroplasty.

A year after the right total hip replacement for primary osteoarthritis of the hip, a patient presented to the hospital with dislocation of femoral head from the acetabulum and dissociation of the head-neck junction after a trivial rotational movement of the lower limb. While waiting for the surgery, spontaneous reduction in dislocated femoral head into the acetabulum and spontaneous relocation of the femoral neck occurred. This rare phenomenon and the possible mechanism of such dissociation and relocation are discussed in this report. Such relocations provide dramatic pain relief to the patient but they are not therapeutic. Revision surgery was required to correct the underlying problem.

Breakage of bioabsorbable femoral transfix screw after arthroscopic anterior cruciate ligament repair: a report of two cases.

The reconstruction of anterior cruciate ligament (ACL) has become the standard of care for a torn ACL in active, young athletes. Various methods, graft options and techniques of reconstruction are published. The use of biotransfix bioabsorbable screw is one of the options of anchoring the graft on the femoral side. We describe the failure of transfix due to breakage in two patients after arthroscopic ACL reconstruction. These patients developed symptoms of screw irritation subcutaneously or skin penetration of the broken, migrated transfix pin. The clinical presentation, diagnosis, the image findings, management and review of literature are presented in this report. To the best of our knowledge, this is the only report from Asia.

Subchondral stress fracture of femoral head in a healthy adult.

Subchondral fracture of the femoral head is an uncommon entity and usually occurs as an insufficiency fracture associated with poor bone quality or as a fatigue fracture in young military recruits. This condition should be considered in the differential diagnosis of acute hip pain in young patients along with transient osteoporosis and avascular necrosis of the hip. We report a case of acute onset hip pain in an asymptomatic healthy adult in which the diagnosis was made by magnetic resonance imaging and the patient responded well to conservative treatment.

A comparison of early and delayed arthroscopically-assisted reconstruction of the anterior cruciate ligament using hamstring autograft.

Delayed rather than early reconstruction of the anterior cruciate ligament is the current recommended treatment for injury to this ligament since it is thought to give a better functional outcome. We randomised 105 consecutive patients with injury associated with chondral lesions no more severe than grades 1 and 2 and/or meniscal tears which only required trimming, to early (< two weeks) or delayed (> four to six weeks) reconstruction of the anterior cruciate ligament using a quadrupled hamstring graft. All operations were performed by a single surgeon and a standard rehabilitation regime was followed in both groups. The outcomes were assessed using the Lysholm score, the Tegner score and measurement of the range of movement. Stability was assessed by clinical tests and measurements taken with the KT-1000 arthrometer, with all testing performed by a blinded uninvolved experienced observer. A total of six patients were lost to follow-up, with 48 patients assigned to the delayed group and 51 to the early group. None was a competitive athlete. The mean interval between injury and the surgery was seven days (2 to 14) in the early group and 32 days (29 to 42) in the delayed group. The mean follow-up was 32 months (26 to 36). The results did not show a statistically significant difference for the Lysholm score (p = 0.86), Tegner activity score (p = 0.913) or the range of movement (p = 1). Similarly, no distinction could be made for stability testing by clinical examination (p = 0.56) and measurements with the KT-1000 arthrometer (p = 0.93). Reconstruction of the anterior cruciate ligament gave a similar clinical and functional outcome whether performed early (< two weeks) or late at four to six weeks after injury.

Effect of solvent polarity on the fluorescence quenching of biologically active 5BAMC by aniline in binary solvent mixtures.

The fluorescence quenching of 5, 6-benzo-4-azidomethyl coumarin (5BAMC) by aniline have been carried in different solvent mixtures of benzene (BN) and acetonitrile (AN) at room temperature by steady state fluorescence measurements. The quenching is found to be appreciable and a positive deviation from linearity was observed in the Stern-Volmer plot for the fluorophore in all the solvent mixtures. Various parameters for the quenching process have been determined using the extended S-V equation and have been found to be dependent on the solvent polarity. Further, with the use of finite sink approximation model, it is concluded that the bimolecular reactions quenching reactions are diffusion limited, and the distance parameter R' and mutual diffusion coefficient D are estimated independently.