Supercapsular percutaneously-assisted total hip arthroplasty: radiographic outcomes and surgical technique

Abstract

Background: The supercapsular percutaneously-assisted total hip (SuperPATH(®)) approach for total hip arthroplasty (THA) was developed to promote early mobilization and greater range of motion, physiologic gait kinematics and improved pain control. The superpath approach is a hybrid of the Superior Capsulotomy (SuperCap(®)) approach and the percutaneously assisted total hip (PATH(®)) technique.

Methods: Postoperative radiographs of 66 consecutive patients from the first 100 patients who underwent the SuperPATH approach were analysed by an independent third party for component position and seating, femoral offset and leg length. A detailed description of preoperative and postoperative preparation, soft tissue dissection, preparation of the femoral canal and acetabulum, and implant positioning is also provided with figures to illustrate.

Results: All components in this case series were well seated and position deemed optimal. Leg lengths were measured to within 5 mm of the contralateral side and mean acetabular abduction angle was 40.13° (SD 6.30°).

Conclusions: Through preservation of the external rotators, hip capsule, and abductor integrity, the SuperPATH approach for THA maximally preserves the surrounding soft tissue envelope. Implant position was optimal within the 'learning curve' of the first 100 cases for described THA safe zones. Long term outcome data for the SuperPATH approach are being collected as part of an ongoing study to compare to favourable short and mid-term results.

Keywords: Arthroplasty; minimally invasive; radiographic outcomes; supercapsular percutaneously-assisted total hip (SuperPATH); technique; total hip replacement.

Conflict of interest statement

Conflicts of Interest: JC Chow is an active consultant for MicroPort Orthopedics Inc., receiving fees for educational purposes. DA Fitch is a paid employee of MicroPort Inc.

Figures

Figure 1

A patient was positioned on a standard peg-board in the “home position” with a foot on a padded Mayo stand.

Figure 2

Following the initial incision, two wing-tipped elevators were used to split the gluteus maximus muscle and expose the underlying gluteus medius muscle.

Figure 3

With the leg in the “home position”, the capsule was incised along the path of the main incision using electrocautery.

Figure 4

The femoral canal was prepared for broaching using starter, metaphyseal and lateralizing reamers.

Figure 5

The femur was broached with the femoral head intact to minimize the risk of femoral neck fracture.

Figure 6

The external portal placement guide was used to ensure accurate placement of a cannula through which acetabular reaming and component impaction was performed.

Figure 7

An appropriately sized acetabular basket reamer was inserted through the main incision and the reamer drive shaft was introduced through the cannula.

Figure 8

Trial components were introduced and assembled in-situ.