Abstract: Objective To summarize the clinical characteristics of hip joint diseases complicated with lumbar degenerative diseases, and to analyze the causes and countermeasures of misdiagnosing them as lumbar degenerative diseases. Methods Cases diagnosed as lumbar degenerative diseases who had poor therapeutic outcomes were collected during Apr. 2013 and Aug. 2020. During the follow-up, 33 patients with hip disease requiring surgical treatment were involved, including 18 males and 15 females, aged from 41 to 79 years, with an average of(51±12)years. Preoperative diagnosis was lumbar spinal stenosis in 24 cases and lumbar disc herniation in 9 cases. Preoperative symptoms included low back pain in 9 cases(27.3%), hip pain in 11 cases(33.3%), greater trochanter pain in 5 cases(15.2%), groin pain in 2 cases(6.1%), anterior/posterior thigh pain in 4 cases(12.1%), knee pain in 5 cases(15.2%), lower leg pain in 3 cases(9.1%), and intermittent claudication in 21 cases(63.6%). Preoperative physical examination included straight-leg raising test(+)in 7 cases, Patrick sign(-)in 19 cases, Patrick sign(+)in 5 cases and no original medical records in 9 cases. Primary lumbar spine operation methods were lumbar lamina fenestration and discectomy in 6 cases, PETD in 2 cases, lumbar laminectomy and decompression in 5 cases, Open-PLIF in 19 cases and MIS-TLIF in 1 case. Results During the average follow-up of(3.4±1.3)years, 21 cases had poor symptom relief and were confirmed 3 months after operation, 10 cases were confirmed 3 months to 1 year after operation, and 2 cases were confirmed more than 1 year after operation. The re-diagnosis results included aseptic necrosis of femoral head in 16 cases(unilateral in 14 cases, bilateral in 2 cases), and acetabular dysplasia complicated with osteoarthritis in 17 cases(unilateral in 16 cases, bilateral in 1 case). Secondary preoperative clinical symptoms were low back pain in 1 case(3.0%), hip pain in 11 cases(33.3%), greater trochanter pain in 5 cases(15.2%), groin pain in 2 cases(6.1%), anterior/posterior thigh pain in 4 cases(12.1%), knee pain in 5 cases(15.2%), lower leg pain in 3 cases(9.1%), and limb in 14 cases(42.4%). Physical examination included straight leg lifting test(+)in 1 case, Patrick sign(-)in 4 cases,(+)in 23 cases and(±)in 6 cases. Conclusion When the imaging examination of lumbar degenerative diseases is inconsistent with the symptoms and signs, we should be alert to the possibility of hip joint diseases. The clinical manifestations of osteoarthritis of hip joint and idiopathic femoral head necrosis are sometimes atypical, which may simply manifests as pain and discomfort in waist and buttocks, and pain can radiate to the front of thigh or similar to sciatica. In patients with hip-spine syndrome, the diagnostic specificity of straight leg lifting test and Patrick sign is not high. Careful preoperative physical examination and necessary imaging screening can effectively reduce misdiagnosis and mistreatment.

Key words: Lumbar vertebrae, Herniated disc, Spinal stenosis, Hip joint, Femur head necrosis, Misdiagnosis