Introduction

• Controversy remains whether the contralateral hip should be fixed or not.

• Proposed indicators – age, gender, weight, bone age, endocrine disorder, symptomatic contralateral hip.

• Posterior slope angle of physis of >12 deg of C/L on axial radiograph.

PSA

Universal C/L Fixation

For• 30-40% incidence- severe

and unpredictable.

Against• Majority does not slip.• Risk of chondrolysis,

subtrochanteric fractures and prolonged surgical time.

• 70% have mild slip; can have FAI and early arthritis later.

Aim

• Comparison between the two groups for –– Complication rate– Functional status– Radiographic evidence of CAM lesions and OA

changes.• Cost analysis of prophylactic fixation of C/L

hip.

Materials and Methods

• 91 pts between Jan 2000 and Dec 2010 with U/L or B/L SCFE.

• 86 recruited. • Excluded- 4 b/l slips with endocrine

abnormalities and one outside catchment area.• Patient residing within the catchment area, who

were treated at hospital. Also included pts who received intial management outside.

• M:F= 54:32• Mean age of 12.3 years• Procedures and decision for C/L hip fixation

decided by consultant.• Single fully/ partially threaded cancellous screw

with atleast three threads across the physis.• Lateral femoral entry point was proximal to LT

and joint penetration avoided.

Data

• Operation register and medical records.• Information obtained-– endocrine dysfunction,– whether they had unilateral or bilateral fixation; if

this was prophylactic or not,– whether a subsequent slip occurred on the

contralateral side

Complications

• infection• screw removal• periprosthetic fracture• chondrolysis• avascular necrosis (AVN)• conversion to THR

• SES estimated by Scottish index of multiple deprivation.– Employment– income and benefits– Recorded crime rates– Housing– health and healthcare use– education– access to services and transport

• Telephonic interview• SF-12 and OHS( Oxford Hip Score)• Radiographs(post 2007; PACS), analysed for

PSA of the physeal slope on AP and frog leg views.

• Most recent x rays assesed for presence of cam lesion and kellgren lawrence grading done for OA.

• Quality adjusted life year (QALY) calculated using difference between health gain between those who underwent fixation and those who did not.

• SPSS, Student t test, Mann whitney U test, Chi square analysis.

Results

• No significant difference in age, gender, associated endocrine abnormality or socioeconomic status.

• 23/50 patients(46%) whi underwent U/L fixation suffered a later slip.(128 d)

C/L SCFE

• 2 patients with implant exit and planned for scopy.

• 1 patient- Severe slip; Southwick osteotomy. Planned for THR at 23 yrs age.

• No deep wound infections, chondrolysis or periprosthetic infection of the C/L hip.

X rays

• Initial x rays showed a significant difference between patients with U/L fixation who didn’t have a later slip and those who did.

Latest radiographs

• 28 (56%) radiographs available for the unilateral group and 31 (86%) available for the prophylactic group.

• In total eight cam lesions were observed, all in the group that did not undergo prophylactic fixation.

• Three of the cam lesions were observed in patients that went on to have a symptomatic slip on the contralateral side

• Two patients with symptomatic FAI and grade 1 changes of OA.

• Five patients who had unilateral fixation only, with no symptomatic further slip on the contralateral side, had cam lesions which were not present at the initial presentation.

Economic Cost

Conclusion

• Patients undergoing prophylactic fixation at the study centre had-– lower rate of complications– better functional outcome– lower rate of radiographic cam lesions

• compared with those who underwent unilateral fixation.

• Cost-effective procedure with a cost per QALY of £1431

Limitation

• Retrospective study• Assumption that all patients had an equal SF-

12-6D score at eight years despite a wide range of follow-up.

• Patients were not randomised to each group, with the choice to perform prophylactic fixation being at the consultant’s discretion.

• Results may help parents make an informed decision when offered prophylactic fixation.

• Study does not offer a definitive answer whether prophylactic fixation should be performed in all patients.

• A prospective multicentre randomised controlled trial is required.