Muscles Encountered During the Lateral (Hardinge) Approach to the Hip
The lateral (Hardinge) approach to the hip involves sequential dissection through skin, subcutaneous tissue, fascia lata, then splitting the anterior fibers of the gluteus medius and minimus muscles in continuity with the vastus lateralis muscle.
Anatomical Layers from Superficial to Deep
Superficial Structures
- Skin and subcutaneous tissue are incised first, typically centered over the greater trochanter 1
- Fascia lata (iliotibial band) is then incised longitudinally 2
Muscle Dissection Sequence
The key distinguishing feature of the Hardinge approach is the splitting of the anterior one-third of the gluteus medius muscle:
- Gluteus medius (anterior fibers) - The anterior one-third of this muscle is split in line with its fibers, leaving the posterior two-thirds intact 1, 2
- Gluteus minimus (anterior fibers) - Dissociated in continuity with the anterior gluteus medius 1
- Vastus lateralis - The anterior gluteal fibers remain continuous with the vastus lateralis, which is elevated as a single unit 1, 2
Deep Access
- Hip joint capsule is then exposed and incised to access the femoral head and acetabulum 2
Critical Anatomical Considerations
The superior gluteal nerve is at significant risk during this approach:
- The nerve innervates the gluteus medius and minimus muscles 3
- Damage occurs in approximately 23% of cases at two weeks postoperatively, with 11% showing persistent complete denervation at nine months 3
- Nerve injury results in abductor weakness and positive Trendelenburg sign 3
Functional differentiation exists within the gluteus medius:
- The deep (anterior) portion functions differently than the superficial (posterior) portion 4
- This anatomical split in the Hardinge approach specifically targets the anterior fibers while preserving posterior abductor function 1
Clinical Implications
The approach provides excellent visualization of both the proximal femur and acetabulum 2, 5, which is why it remains widely used for total hip arthroplasty despite the risk of abductor dysfunction 6.
Residual abductor deficiency occurs in approximately 33% of patients at one year, compared to 17% with posterior approaches 1. This manifests as moderate to severe limp in 10% of all patients and 4% of patients with unilateral hip disease at two-year follow-up 2.
The dislocation rate is notably low (0.3-2.5%) compared to posterior approaches 2, 5, which historically justified acceptance of the higher abductor weakness rate 6.