Patellofemoral joint arthroplasty: patient selection,surgical technique and outcomes

Isolated patellofemoral arthritis is an increasingly recognized entity, and is usually associated with previous patellofemoral dysplasia or instability. Patellofemoral arthroplasty (PFA) has evolved significantly in recent years, both in terms of implant design and importantly in the understanding of appropriate patient selection. This review outlines the indications and investigations for PFA, provides a brief history of the development of contemporary implants, and presents the clinical outcomes for the prostheses most commonly used in the UK. In addition, it provides a detailed surgical technique for implantation of an onlay implant, with tips on how to optimize patellofemoral biomechanics and thus achieve a consistently good outcome.     

Chorioretinal folds and a macular hole secondary to craniofacial surgery

Chorioretinal folds have been reported as a result of many intraocular and extraocular inflammatory processes or tumors. Visual loss is usually secondary to a combination of the underlying process and chorioretinal folds involving the macula. We report a patient who developed decreased vision, metamorphopsia, chorioretinal folds, and a lamellar macular hole secondary to global compression by a bone fragment. The chorioretinal folds regressed and his vision stabilized following surgical decompression. Chorioretinal folds and lamellar macular hold formation are previously unrecognized complications of reconstructive craniofacial surgery.     

Neonatal vocal cord paralysis following extracorporeal membrane oxygenation

Five cases of unilateral vocal cord paralysis/paresis were diagnosed following extracorporeal membrane oxygenation for newborn respiratory failure. All were right sided and transient in nature. None of the five patients had other findings commonly associated with vocal cord palsy. The extracorporeal membrane oxygenation procedure requires surgical dissection in the carotid sheath on the right side of the neck, an area immediately adjacent to both the vagus and recurrent laryngeal nerve. It is speculated that vocal cord paralysis in these infants was acquired as a result of the extracorporeal membrane oxygenation cannulation. Although the vocal cord paralysis resolved in all cases, two patients had difficult courses after extracorporeal membrane oxygenation. Therefore, laryngoscopic examination should be considered for patients after extracorporeal membrane oxygenation.     

Pressure distribution and perceived comfort in casual footwear

The aim of this investigation was to establish the relationship between short-term perceived comfort and pressure distribution on the dorsal and plantar surfaces of the foot, while walking in a range of commercially available casual footwear. The study was carried out in the biomechanics laboratory of Manchester Metropolitan University using 15 male subjects without foot pathology. Perceived upper and plantar comfort were measured using a specially designed questionnaire, while dorsal and plantar pressure distributions were measured using a rectangular sensor pad recording at 30 Hz and a Mikro-EMED insole recording at 100 Hz respectively. Analysis of variance tests were used to determine differences in perceived comfort and pressure distribution between three pairs of shoes. The findings of this study suggest that an increase in total plantar force and force-time integral may relate to a decrease in perceived plantar comfort. For the three shoes examined in this study, overall peak plantar pressure, the pressure-time integral, and total plantar area did not appear to be linked to perceived plantar comfort. Findings for the shoe upper indicate that decreased dorsal forces and pressures may be related to decreased upper comfort. These findings suggest that the measurement of pressure distribution at the foot-shoe interface could be a useful tool in identifying the causes of discomfort in footwear.