Biomedical subjects

Alastair S E Younger

Publications and source records attributed to Alastair S E Younger.

8 recordsLinked to original sources

PubMed2006

Reconstruction of the infected traumatized joint.

This article discusses reconstruction of the infected traumatized joint. In some cases the injured joint has posttraumatic arthritic change, and the surgeon is challenged with known or potential infection that confounds the treatment plan. Failure to treat the associated deep infection adequately results in failure to achieve the surgical goals. Ongoing infection can compromise the soft tissue envelope significantly by sinus tract formation or inflammation. The local bone may be eroded or softened which compromises the reconstructive alternatives. Attempted fusion in the face of undiagnosed and untreated infection may cause the fusion to fail. All of these issues can result in a below-knee amputation.

Ankle Injuries↗

PubMed2006

Soft tissue coverage for posttraumatic reconstruction.

Posttraumatic foot and ankle reconstruction requires careful preoperative planning to reduce wound complications. Systemic and local factors need to be considered. A careful surgical technique can avoid the need for surgical soft tissue coverage. Recognition of the need for coverage preoperatively improves outcomes. Often, dressings and time allow minor wound complications to heal. More severe wound issues require early soft tissue coverage by local or free flaps to prevent failure of the surgery.

Ankle Injuries↗

PubMed2006

Anatomic reconstruction of the lateral ligament complex of the ankle using a gracilis autograft.

Many techniques have been described for surgical management of lateral ankle instability. Anatomic repair and nonanatomic reconstruction have higher recurrence rates, and may be complicated by ankle stiffness. Anatomic reconstruction should be considered in stabilization for deficiencies of the lateral ankle ligament complex, as the initial construct is stronger while maintaining normal ankle mechanics.

Foot↗

PubMed2006

Anatomic repair for chronic lateral ankle instability.

Symptomatic ankle instability will develop in upto 20% of patients after inversion injury. Although most patients can be successfully managed with rehabilitation and bracing, some will continue to suffer recurrent ankle instability with activities of daily living, work on uneven terrain, or sports. For this group of patients, we advocate direct anatomic surgical repair with the Brostrom procedure with or without its modifications.

Chronic Disease↗

PubMed2005

Survey of tourniquet use in orthopaedic foot and ankle surgery.

BACKGROUND: Tourniquet technique varies among foot and ankle surgeons, and to establish a standard practice guideline the current standard of care should be examined. METHODS: One hundred and forty responses were received after 253 surveys were mailed to American Orthopaedic Foot and Ankle Society (AOFAS) members, concerning type of tourniquets, location, and pressures used. RESULTS: Cuff pressures most commonly used were 301 to 350 mmHg for thigh cuffs (49% of thigh cuff users) and 201 to 250 mmHG for calf and ankle cuffs (52% of calf cuff users, 66% of ankle cuff users). A substantial number of foot and ankle surgeons who use calf and ankle cuffs frequently use pressures above 250 mmHg (41% of calf cuff users, 19% of ankle cuff users). Only 9% use limb occlusion pressure when determining cuff pressure. CONCLUSION: Based on the existing evidence-based literature these pressures may be higher than necessary for many patients, and increased adoption of optimal pressure setting techniques as reported in the literature may help reduce tourniquet pressures used and risk of tourniquet injury. Respondents reported experiencing or hearing reports of breakthrough bleeding, nerve injury, and skin injuries under the cuff.

Ankle↗

PubMed2005

Adult cavovarus foot.

Cavovarus foot deformity, which often results from an imbalance of muscle forces, is commonly caused by hereditary motor sensory neuropathies. Other causes are cerebral palsy, cerebral injury (stroke), anterior horn cell disease (spinal root injury), talar neck injury, and residual clubfoot. In cavovarus foot deformity, the relatively strong peroneus longus and tibialis posterior muscles cause a hindfoot varus and forefoot valgus (pronated) position. Hindfoot varus causes overload of the lateral border of the foot, resulting in ankle instability, peroneal tendinitis, and stress fracture. Degenerative arthritic changes can develop in overloaded joints. Gait examination allows appropriate planning of tendon transfers to correct stance and swing-phase deficits. Inspection of the forefoot and hindfoot positions determines the need for soft-tissue release and osteotomy. The Coleman block test is invaluable for assessing the cause of hindfoot varus. Prolonged use of orthoses or supportive footwear can result in muscle imbalance, causing increasing deformity and irreversible damage to tendons and joints. Rebalancing tendons is an early priority to prevent unsalvageable deterioration of the foot. Muscle imbalance can be corrected by tendon transfer, corrective osteotomy, and fusion. Fixed bony deformity can be addressed by fusion and osteotomy.

Adult↗

PubMed2004

Biomechanics of external fixation and limb lengthening.

Surgeons who use external fixators for foot and ankle conditions need to understand the biomechanical principles to ensure good outcomes. Fixators can be used for fracture fixation, correction of contractures, distraction osteogenesis, and distraction arthroplasty. A two-ring fixator with wire fixation remains the gold standard with which all other frames are compared. Small changes in mechanical characteristics can have major implications on new bone or cartilage formation.

Acute Disease↗

PubMed2004

Wide contoured thigh cuffs and automated limb occlusion measurement allow lower tourniquet pressures.

We examined the amount of thigh tourniquet pressure that can be reduced from the typical 300 to 350 mm Hg by using a new automated plethysmographic limb occlusion pressure measurement technique. We also examined how much pressure could be reduced by using a wide contoured cuff compared with a standard cuff and if limb occlusion and systolic blood pressures were well correlated. Patients having surgery with a thigh tourniquet were randomized into two groups, one group having surgery with a standard cuff and the other with a wide cuff. Pressure was set at the automatically measured limb occlusion pressure plus a safety margin. Systolic blood pressure and quality of the bloodless field were recorded. The standard cuff maintained an acceptable bloodless field for 18 of 20 patients at an average pressure of 242 mm Hg, and the wide cuff was acceptable for 19 of 20 patients at an average of 202 mm Hg. One patient in each group had a poor bloodless surgical field at the initial pressure, and one patient in each group had a poor bloodless surgical field after a sharp rise in blood pressure during surgery. Systolic blood pressure was not correlated well enough to limb occlusion pressure to be used alone to set the optimum cuff pressure. The automated limb occlusion pressure technique and the wide contoured cuff reduced average pressure by 33-42% from typical pressures.

Adult↗