Southwick (1967) describes a systematic biplane wedge osteotomy at the lesser trochanter for SCFE with 30–70° of slipping. Correction angles are calculated from AP and frog-leg lateral head-shaft angle measurements compared to the normal side. The paper reports outcomes in 55 treated patients, addressing whether this extracapsular approach can correct deformity while avoiding the AVN associated with neck-level procedures.
Before this paper, correcting severe SCFE meant operating at or near the femoral neck — a region where the blood supply is so vulnerable that AVN complicated 25–33% of procedures. The Southwick osteotomy shifted correction distally to the lesser trochanter, below the arterial ring, and achieved zero AVN in 55 patients.
When you see a teenager with SCFE and 30–70° of fixed posterior tilting or varus, this is why you measure the head-shaft angle on both AP and frog-leg lateral radiographs: the difference between sides tells you exactly how much wedge to remove. Keep the AP wedge under 45° to avoid excessive valgus, and the lateral wedge under 60° to avoid shortening.
If post-operative joint-space narrowing appears, do not rush to reconstruction. The paper documents spontaneous reversal over 2–3 years and advises waiting at least 3 years before any salvage procedure. The Southwick angle remains a standard measurement in SCFE classification and pre-operative planning. Understanding its derivation from this paper clarifies both its use and its limits.
Southwick (1967) describes a systematic biplane wedge osteotomy at the lesser trochanter for SCFE with 30–70° of slipping. Correction angles are calculated from AP and frog-leg lateral head-shaft angle measurements compared to the normal side. The paper reports outcomes in 55 treated patients, addressing whether this extracapsular approach can correct deformity while avoiding the AVN associated with neck-level procedures.
Before this paper, correcting severe SCFE meant operating at or near the femoral neck — a region where the blood supply is so vulnerable that AVN complicated 25–33% of procedures. The Southwick osteotomy shifted correction distally to the lesser trochanter, below the arterial ring, and achieved zero AVN in 55 patients.
When you see a teenager with SCFE and 30–70° of fixed posterior tilting or varus, this is why you measure the head-shaft angle on both AP and frog-leg lateral radiographs: the difference between sides tells you exactly how much wedge to remove. Keep the AP wedge under 45° to avoid excessive valgus, and the lateral wedge under 60° to avoid shortening.
If post-operative joint-space narrowing appears, do not rush to reconstruction. The paper documents spontaneous reversal over 2–3 years and advises waiting at least 3 years before any salvage procedure. The Southwick angle remains a standard measurement in SCFE classification and pre-operative planning. Understanding its derivation from this paper clarifies both its use and its limits.