Trochanteric Bursa Repair and Lateral Hip Pain After Hemiarthroplasty for Femoral Neck Fracture

This is a prospective, single-center, parallel-group, randomized controlled trial designed to evaluate the effect of trochanteric bursa repair on early postoperative lateral hip pain in patients aged 65 years and older undergoing primary hemiarthroplasty for acute intracapsular femoral neck fractures.

Background and Rationale

The trochanteric bursa facilitates gliding between the greater trochanter and the surrounding soft tissues. During posterior approach hip arthroplasty, the bursa may be longitudinally incised to obtain surgical exposure. Whether repairing this tissue at the end of surgery reduces postoperative lateral trochanteric pain remains uncertain.

Previous studies have primarily investigated trochanteric bursa management during total hip arthroplasty. Evidence specifically addressing bursa repair versus leaving the bursa unrepaired in older patients undergoing hemiarthroplasty for femoral neck fractures is limited.

Study Design and Randomization

A total of 102 participants will be randomized in a 1:1 ratio to either trochanteric bursa repair (n=51) or no bursa repair (n=51).

Randomization will use a computer-generated variable block sequence prepared by an independent investigator. Group allocation will be concealed using sequentially numbered, opaque, sealed envelopes.

During surgery, the operating surgeon will assess the integrity and suitability of the trochanteric bursa for primary anatomical repair before group allocation is revealed. Only patients with a bursa suitable for repair will undergo randomization.

Surgical Interventions

All patients will undergo primary hip hemiarthroplasty through a posterior surgical approach.

In the intervention group, the longitudinally opened trochanteric bursa will be anatomically repaired using three to four interrupted sutures with No. 1 Vicryl.

In the control group, the trochanteric bursa will be left unrepaired following the same longitudinal opening.

The trochanteric bursa will not be excised in either group. Capsular and short external rotator repair, implant system, postoperative analgesia, mobilization, and rehabilitation will follow the same routine clinical protocols in both groups.

Blinding

The operating surgical team cannot remain blinded after group allocation because of the nature of the intervention. Postoperative physiotherapists, outpatient outcome assessors, and radiographic assessors will remain blinded to treatment allocation. Complete participant blinding cannot be guaranteed.

Outcome Assessment

The primary outcome is lateral trochanteric pain experienced while lying on the operated side at six weeks postoperatively, assessed using an 11-point Numerical Rating Scale (NRS; 0-10), with higher scores indicating greater pain.

Secondary outcomes include lateral hip pain during daily activities, pain on trochanteric palpation, ability to lie on the operated side, mobility assessed using the Turkish version of the Cumulated Ambulation Score (CAS-TR), functional independence assessed using the Modified Barthel Index, and intraoperative and postoperative complications.

Preoperative assessments include cognitive and delirium screening using the Standardized Mini-Mental Test and 4AT, together with pre-fracture functional assessments.

Postoperative day 1 mobilization status and postoperative day 2 CAS-TR, 4AT, and early complications will be recorded. Follow-up assessments will be performed at 2, 4, and 6 weeks and at 3 months after surgery.

Radiographic assessments will use existing routine postoperative anteroposterior pelvic radiographs. No additional radiographs will be obtained solely for research purposes.

Statistical Analysis

The primary analysis will compare six-week side-lying lateral hip pain NRS scores between randomized groups among participants with an evaluable primary outcome, according to their assigned treatment. Between-group mean differences, 95% confidence intervals, and two-sided p-values will be reported. Repeated pain and functional measurements will be analyzed using mixed-effects models.

Missing primary outcome measurements, including those due to death, inability to lie on the operated side, or inability to provide a reliable pain rating, will be documented without assigning artificial pain scores.

Protocol and Statistical Analysis Plan Details

Neither arm will receive trochanteric bursa excision or a study-related steroid injection. The independent assistant physician preparing the randomization sequence will not participate in participant selection, surgery, or outcome assessment. The 001-102 allocation envelopes will be held in one ordered box; operating-room personnel will open the next envelope only after intraoperative bursa repairability has been confirmed. Envelope opening defines randomization. Complications or intervention deviations after randomization will not lead to removal of the randomization record or reassignment.

Follow-up targets are calculated from the date of surgery. Visit windows are plus or minus 3 days at weeks 2, 4, and 6, and plus or minus 7 days at month 3; actual visit dates will be recorded. Pain NRS and Modified Barthel assessments are not scheduled on postoperative day 2. For radiographic reconstruction measurements, one best suitable routine AP pelvis radiograph from the early postoperative period through month 3 will be selected and assessed by one blinded reader. Radiographic differences will not be used to exclude randomized participants.

Sample Size

Assuming a between-group difference of 1.0 NRS point and a common standard deviation of 1.4, a two-sided alpha of 0.05 and 90% power require 43 evaluable participants per group. Allowing approximately 15% loss or non-evaluability, 51 participants per group (102 total) will be randomized. These planning assumptions are extrapolated from total hip arthroplasty studies using VAS and are not directly observed six-week NRS data from this hemiarthroplasty population.

Prespecified Analysis

The primary evaluable population consists of randomized participants alive at week 6 with a reliably obtained operated-side lying lateral pain NRS. The primary effect will be estimated by unadjusted linear regression as the repair-minus-control mean difference, with a 95% confidence interval, effect size, and two-sided p-value (alpha 0.05), according to randomized assignment regardless of the intervention received. Robust standard errors will be used if model residual assumptions are substantially inappropriate; Mann-Whitney U testing and an appropriate confidence interval for the median difference will provide a sensitivity analysis.

A supporting adjusted regression will include prespecified age, sex, pre-fracture CAS-TR, classical Charlson Comorbidity Index (without age points), and cemented versus uncemented stem status. Covariates will not be selected using observed outcomes or univariate p-values. Repeated NRS, CAS-TR, and Modified Barthel measurements will use mixed-effects models with participant-level random intercepts and group, time, and group-by-time fixed effects; baseline values will be included where appropriate. Categorical outcomes will use chi-square or Fisher exact tests; day 1 mobilization will be summarized or analyzed using an appropriate ordinal method. Secondary analyses are supportive and exploratory.

Missingness due to death, loss to follow-up, not lying on the operated side, unreliable NRS reporting, or other reasons will be reported separately by group. No hypothetical NRS will be assigned. Prespecified sensitivity analyses will examine major complications affecting lateral pain, assessments outside visit windows, and nonparametric assumptions. Multiple imputation or mixed-model supporting analyses may be used when the amount and pattern of missingness justify them; outcomes after death will remain unassigned. Surgeon and cement-type interactions will be exploratory only if sufficient data are available. No interim efficacy/futility analysis, internal pilot, or sample-size re-estimation is planned.

• Trochanteric Bursa Repair (Procedure): Patients will undergo primary hip hemiarthroplasty through a posterior approach. After longitudinal incision of the trochanteric bursa, the bursa will be anatomically repaired using three to four interrupted No. 1 Vicryl sutures. The bursa will not be excised. Capsular and short external rotator repairs will be performed according to the same standard surgical protocol in both groups.
• Trochanteric Bursa Left Unrepaired (Procedure): Patients will undergo primary hip hemiarthroplasty through a posterior approach. After longitudinal incision, the trochanteric bursa will be left unrepaired without excision. All other surgical procedures, postoperative analgesia, mobilization, and rehabilitation will follow the same protocol as the bursa repair group.

Primary outcomes

• Lateral Trochanteric Pain While Lying on the Operated Side at Week 6 [Postoperative week 6]: Lateral trochanteric pain experienced while lying on the operated side during the preceding 7 days will be assessed using an 11-point Numeric Rating Scale (NRS), ranging from 0 (no pain) to 10 (worst imaginable pain). Lower scores indicate less pain. If the participant has not lain on the operated side during the preceding 7 days, no hypothetical NRS score will be assigned; the reason will be recorded separately.

Secondary outcomes

• Lateral Trochanteric Pain During Daily Activities [Postoperative weeks 2, 4, and 6, and month 3]: Pain in the lateral trochanteric region during daily activities over the preceding 7 days will be assessed using an 11-point Numeric Rating Scale (NRS), ranging from 0 (no pain) to 10 (worst imaginable pain). Lower scores indicate less pain.
• Lateral Trochanteric Pain While Lying on the Operated Side [Postoperative weeks 2, 4, and 6, and month 3]: Pain experienced while lying on the operated side during the preceding 7 days will be assessed using an 11-point Numeric Rating Scale (NRS), ranging from 0 (no pain) to 10 (worst imaginable pain). No hypothetical score will be assigned if the participant has not lain on the operated side. The week 6 measurement is also the primary outcome and will be included in the longitudinal analysis.
• Greater Trochanter Tenderness on Palpation [Postoperative weeks 2, 4, and 6, and month 3]: Pain elicited by approximately 2 to 3 seconds of standardized moderate pressure over the most prominent lateral point of the greater trochanter will be measured using an 11-point Numeric Rating Scale (NRS), ranging from 0 (no pain) to 10 (worst imaginable pain).
• Cumulated Ambulation Score (CAS-TR) [Preoperative baseline (retrospective pre-fracture status), postoperative day 2, weeks 2, 4, and 6, and month 3]: Basic mobility will be assessed using the Turkish version of the Cumulated Ambulation Score (CAS-TR). The score evaluates getting in and out of bed, rising from a chair, and walking. Each activity is scored from 0 to 2, yielding a total score from 0 to 6. Higher scores indicate greater mobility independence. Pre-fracture mobility will be assessed retrospectively at baseline.
• Modified Barthel Index [Preoperative baseline (retrospective pre-fracture status), postoperative weeks 2, 4, and 6, and month 3]: Independence in activities of daily living will be assessed using the Modified Barthel Index. The index evaluates functional independence in daily activities, including feeding, bathing, dressing, toileting, transfers, and mobility. Higher scores indicate greater independence. Pre-fracture functional status will be assessed retrospectively at baseline. Total scores range from 0 to 100.
• Ability to Lie on the Operated Side [Postoperative weeks 2, 4, and 6, and month 3]: The ability to lie on the operated side during the preceding 7 days will be recorded. The proportion of participants able to lie on the operated side will be evaluated. For those who have not done so, the reason will be categorized as pain, fear of pain, another reason, or unable to assess.
• Mobilization Level on Postoperative Day 1 [Postoperative day 1]: Mobilization will be assessed by a physiotherapist blinded to group allocation and classified into four categories: unable to get out of bed; stood up but did not walk; walked using a walker; or walked independently without human assistance. If mobilization is not achieved, the reason will be documented.
• 4AT Delirium Assessment Score [Postoperative day 2]: Delirium-related cognitive status will be assessed using the 4AT screening instrument. The 4AT evaluates alertness, orientation, attention, and acute change or fluctuating course. Total scores range from 0 to 12; higher scores indicate greater likelihood of delirium or cognitive impairment. Postoperative day 2 scores will be recorded.
• Intraoperative and Postoperative Complications [Intraoperatively and through postoperative month 3]: The occurrence and type of intraoperative and postoperative complications will be recorded, including early and late complications. Reoperation, hospital readmission, and death will also be documented. Events will be summarized by randomized treatment group. Recorded events include greater trochanter or periprosthetic femoral fracture, wound problems, hematoma/seroma, superficial or deep infection, dislocation, and other serious complications. The type and date of each event will be documented; numbers and proportions of participants with events will be reported by group.
• Femoral Offset Difference on AP Pelvis Radiograph [One suitable routine AP pelvis radiograph obtained between the early postoperative period and month 3]: Femoral offset will be measured in millimeters as the perpendicular distance from the center of the femoral or prosthetic head to the longitudinal axis of the femoral shaft. The difference between operated and contralateral sides will be calculated as operated minus contralateral offset. Only radiographs suitable for reliable measurement will be used.
• Radiographic Leg Length Difference [One suitable routine AP pelvis radiograph obtained between the early postoperative period and month 3]: Radiographic leg length difference will be measured in millimeters using a horizontal reference line through the acetabular teardrops and the perpendicular distances to the lesser trochanter landmarks. The difference will be calculated as operated minus contralateral side; positive values indicate radiographic lengthening of the operated side.
• Femoral Stem Coronal Alignment [One suitable routine AP pelvis radiograph obtained between the early postoperative period and month 3]: Coronal alignment of the femoral stem will be evaluated on a suitable routine anteroposterior pelvis radiograph relative to the longitudinal axis of the femoral shaft. Stem alignment will be documented as a radiographic reconstruction variable. Alignment will be classified as varus, neutral, or valgus by a single assessor blinded to randomized group.
• Early Radiographic Complications [Early postoperative period through postoperative month 3]: Early radiographic complications related to the hemiarthroplasty will be recorded from available routine postoperative radiographs. No additional radiographs will be obtained solely for research purposes. Events include dislocation, greater trochanter fracture, periprosthetic femoral fracture, and other clinically meaningful early radiographic complications, assessed by a single assessor blinded to randomized group.

Sex: All, ages: 65 Years to any

Inclusion Criteria:

* Age 65 years or older.
* Acute unilateral intracapsular femoral neck fracture.
* Primary hip hemiarthroplasty planned through a posterior approach.
* Sufficient capacity to decide on participation and provide personal written informed consent.
* Ability to understand and reliably use the 0-10 Numeric Rating Scale (NRS).
* Intraoperative confirmation, before allocation is revealed, that the trochanteric bursa has sufficient tissue integrity and edges that can be approximated for primary anatomical repair.

Exclusion Criteria:

* Intertrochanteric, pertrochanteric, subtrochanteric, or pathological fracture.
* Revision hemiarthroplasty or salvage hemiarthroplasty after failed internal fixation.
* Previous surgery on the affected hip.
* Clinically significant recurrent or persistent ipsilateral lateral trochanteric pain, greater trochanteric pain syndrome, or trochanteric bursitis during the preceding 6 months. A single brief, clinically insignificant episode of nonspecific pain is not sufficient for exclusion.
* Therapeutic injection into the affected hip joint, trochanteric bursa, or peritrochanteric soft tissues during the preceding 6 months.
* Active local infection.
* Major concomitant lower-extremity injury that independently and severely impairs mobilization.
* Inability to provide valid personal written informed consent or reliably use the NRS.
* Trochanteric bursal tissue unsuitable for primary repair because of major tissue loss, severe fragmentation, or loss of integrity preventing primary approximation; these patients will not be randomized.

No automatic exclusion threshold is applied to the Standardized Mini-Mental Test. Dementia or cognitive impairment alone is not an exclusion criterion if personal informed consent and reliable NRS assessment are possible. A patient who cannot be assessed because of acute delirium may be reassessed if clinically improved before surgery. Proxy consent does not replace the patient's personal consent.

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• Ersin Taşatan, MD, Principal investigator, Istanbul Prof. Dr. Cemil Tascioglu City Hospital, Department of Orthopaedics and Traumatology