Early dislocation in primary total hip arthroplasty: Evaluation of treatment options following closed reduction

Table 1 Classification of instability after total hip arthroplasty according to Wera et al[11] (modified)

Type	Etiology	Diagnosis	Treatment
I	Acetabular component malposition	Anteroposterior pelvic radiograph: Calculate acetabular version by arcsin (1); pelvic CT: Calculate version	Revision of the acetabular component
II	Femoral component malposition	Pelvic and knee CT performed in same sequence: Measure version	Revision of the femoral component
III	Abductor insufficiency	MARS-MRI: Evaluate abductor soft tissue; gait test: Evaluate for Trendelenburg limp	Constrained liner; some authors have had success with dual mobility components
IV	Impingement	Intraoperative detection: Evaluate for subtle signs of wear on the femoral neck and acetabular metal rim; when performing a full range of motion, check for impingement in all degrees of motion	Remove offending impingement structures
V	Late wear	Anteroposterior pelvic radiograph: Migration of the femoral head superiorly and laterally	Liner exchange; curettage and bone-grafting of the osteolysis for contained defects
VI	Unknown etiology	Unable to be determined based on plain radiograph and advanced imaging	Constrained liner
VII	Spinopelvic imbalance	Sitting and standing lateral radiographs: Evaluate sacral tilt; determine pelvic motion as normal, hypermobile or stiff; and then evaluate cup position and determine anteversion and inclination	Anterversion and inclination of the cup varies based on the position of the acetabular component

CT: Computed tomography; MARS-MRI: Magnetic resonance angiography with susceptibility weighting.

Table 2 Current role of patient-related risk factors for predisposing to dislocation after primary total hip arthroplasty

Risk factor	Confirmed
Weight	Not
Height	Not
Sex	Not
Age	Not definitively
Femoral neck fracture	Not definitively
Parkinson disease	Not definitively
Cerebral palsy and muscular dystrophy	Yes
Dementia and psychosis	Yes
Previous hip surgery	Yes
Alcohol abuse	Yes
Patient compliance	Yes
Lumbar spine stiffness	Yes

Table 3 Data obtained from papers concerning total hip arthroplasty dislocation, including methods of treatment and related outcome, n (%)

Ref.	Year	Total hip arthroplasty	Early dislocations	Treatment	Recurrence (%)	Follow-up
Ritter[15]	1976	502	7	ABD brace	2 (28.6)	NA
Williams et al[16]	1982	1030	13 (non-surgical); 19 (surgical)	16 cast for 6 weeks	1 (6.25)	32 months
Dorr et al[17]	1983	NA	39; type I; type II; type III	ABD brace for 4-6 weeks; ABD brace + revision if needed; revision	23 (59)	NA
Clayton and Thirupathi[18]	1983	289	9	Brace for 6-9 months in case of recurrence	1 (11)	NA
Dorr et al[19]	1998	NA	37; type I (11); type II (12); type III (14)	ABD brace for 4-6 weeks; ABD brace + revision if needed; revision	(45); (82); (NA)	5 years
Joshi et al[20]	1998	NA	59 (161)	52% rest in bed for 10 days; 28% skin traction applied to the lower limb; 9% ABD brace; 6% cast; 5% trans-tibial tuberosity traction	15 (25)	8 years
Yuan and Shih[21]	1999	2728	62 (total 97); posterior instability (39%); soft tissue imbalance (13%); component malposition (48%)	1-2 weeks of skin traction applied to the lower limb for all cases. In case of recurrence: 4-6 weeks ABD brace; 3 months ABD brace; NA	(44)	5.3 years
DeWal et al[22]	2004	NA	91	45 no brace; 46 ABD brace	(64); (61)	4 years
Leichtle et al[23]	2013	5205	24 (total 56)	25% anti-rotational cast; 18% Hohmann bandage; 46% anti-rotational cast + bandage; 11% no treatment	11 (45.8)	NA
Ogonda et al[24]	2022	8606	218	Spica or long leg cylinder cast in case of recurrence + revision if needed	(45.6)	20 years

NA: Not available.