Table 2.

Review of the literature

Study	Number of cases	Quantity evaluation of IKP	Diagnosis	Symptoms	Followup after treatment
Crawford et al. [8]	1	No	OA	No hip pain, only IKP	Knee pain relieved after injection to hip
Emms et al. [10]	1	No	OA	No hip pain, only IKP	Knee pain relieved after injection to hip, and THA
Flatman [12]	1	No	Tuberculosis	No hip pain, only IKP	No treatment
Guss [13]	1	No	Hip fracture	No hip pain, only IKP	Pain relieved after THA
Hammer [15]	1	No	Hip fracture	No hip pain, only IKP	Hemiarthroplasty, pain relieved
Hetsroni & Weigl [16]	1	No	Posterior hip dislocation	Hip and knee pain	Closed reduction, pain relieved
Khan et al. [21]	60	No	OA	68.6% had anterior knee pain, 50.9% had posterior knee pain	No treatment
Lesher et al. [24]	51	No	Awaiting hip arthroplasty, no details	Most common site is buttock, 2% to the knee	Pain relieved after injection to the hip
Street et al. [33]	236	No	Awaiting hip arthroplasty, no details	32% had IKP	No IKP data after hip arthroplasty
Current study	255	Yes	OA, osteonecrosis, implant loosening, dysplasia, other	55.3% had IKP which is more than CKP (17.6%), IKP score (79.7) is lower than CKP score (94.8).	IKP improved after hip arthroplasty to the same level of the CKP

IKP = ipsilateral knee pain; CKP = contralateral knee pain; OA = osteoarthritis.