Usefulness of an Extensible Trial Neck in Total Hip Arthroplasty

Maintaining appropriate soft tissue tension is essential in total hip arthroplasty (THA). Surgeons generally achieve this by altering the neck length. However, experimenting with different neck lengths is time-consuming, as it requires repeated hip dislocations. To address this, we have used a new extensible trial neck device that allows for easy adjustment of neck length during surgery. This device can help surgeons avoid the need for repeated hip dislocations to determine the correct neck size. The objective of this research was to investigate whether this device could help shorten operative times and decrease surgical invasion for patients.

Patients undergoing THA were randomly separated into two groups. The first group used the extensible trial neck during trial reduction after the stem and cup were placed (group M), while the second group used a conventional trial neck (group C). Operative time, blood loss, number of additional dislocations needed during the operation, and C-reactive protein (CRP) and creatine phosphokinase (CPK) levels after the operation were compared.

Operative time was significantly shorter and the number of additional dislocations required to choose the final neck size was significantly lower in group M compared with group C. No significant difference in blood loss was observed. CRP and CPK levels days 3 and 7 after surgery decreased in group M compared with group C.

The extensible trial neck was useful for THA by greatly reducing operative time and stress on the patient. [Orthopedics. 2025;48(2):e88-e93.].