How Do You Know if Your Hip Replacement Has Dislocated

Curr Rev Musculoskelet Med. 2013 Dec; 6(iv): 350–356.

Dislocation later total hip arthroplasty

A. Zahar

HELIOS ENDO-Klinik Hamburg, Holstenstraße 2, 22767 Hamburg, Germany

A. Rastogi

Banaras Hindu University, Varanasi, India

D. Kendoff

HELIOS ENDO-Klinik Hamburg, Holstenstraße 2, 22767 Hamburg, Germany

Abstract

Dislocation remains one of the most mutual complications later total hip arthroplasty, regardless of the surgical approach. While multiple reasons as laxity, implant position, improper implant choice, and impingement etc. might exist leading factors for dislocation, an verbal identification of the exact reason is of major importance, to program for a proper surgical or nonsurgical correction. This article describes in detail the definition, etiology, reduction, and possible treatment options for dislocation after master and revision total hip arthroplasty that are currently used at the Endo Klinik in Hamburg. Information technology furthermore includes a distinct overview of possible surgical treatment options, based on the chief pathology leading to dislocation.

Keywords: Dislocation, Surgical approach, Head size, Closed reduction, Open reduction

Introduction

Dislocation after total hip arthroplasty (THA) is the most common early complication following primary implantation [1]. For example, the Swedish Hip Arthroplasty Annals has tracked the number of dislocations until the year 2000, which has conspicuously shown that dislocation, in both cemented and uncemented THA, is considered to be the number one short-term complexity requiring a reoperation within the beginning 2 years [2].

The incidence of dislocation after primary THA is reported from 0.two%–1.7%; the Swedish nation-wide mean rate is reported to exist 0.half-dozen% [ii, iii•]. At THA revision, the reported revision rate because of dislocation tin be 10-fold higher [4, 5].

The posterior approach seems to be at higher risk for dislocation and possible early on reoperation, despite all of its advantages [6].

Definition

The articulation of the prosthetic head and the acetabular liner allow for a range of motion almost close to that of the physiologic values of the intact anatomic hip. Dislocation occurs if the head moves out of the acetabular component for any reason. In 75% of the cases, the prosthetic head dislocates posteriorly.

Typical clinical signs of dislocation include leg shortening with either external or internal rotation, in combination with a pathologic and painful telescoping of the limb. Often, the patients report a sudden onset of pain with a kind of snapping feeling, followed by being unable to walk or load the afflicted leg. Conventional radiographs or physical examination nether fluoroscopy is usually needed for an authentic documentation afterwards dislocation.

Localization of dislocation

Posterior dislocation occurs in flexion-adduction and internal rotation of the hip. The anterior aspect of the implant neck impinges with the anterior acetabular rim, and the head dislocates from the socket. After a posterior approach, the capsule and the curt external rotators are weakened or damaged, facilitating a posterior dislocation [7]. Theoretically, the leg is internally rotated and shortened considering of the entrapment of the head behind the acetabulum, being unable to rotate externally. This is usually associated with a relevant shortening and external rotation of the limb.

Anterior dislocation occurs if the hip is extended, adducted, and externally rotated. Soft tissue impingement or osteophytes at the posterior aspect of the joint along with absence or weakening of the anterior capsule may lead to anterior dislocation, which is more than frequently associated with any anterior approach to the hip joint.

Etiology

Laxity of the hip articulation for any reason is the most obvious gene leading to a dislocation. Shortening of the original neck length past improper choice of the head-neck length ratio is one of the reasons, but this technical mistake occurs quite infrequently [8]. Mail-traumatic hips are more than likely to dislocate even subsequently proper implantation [6]. In revision cases, it is more common that soft tissue tension gradually decreases within the offset weeks afterwards operation even later proper restoration of the center of rotation [3•]. Intraoperative assessment of the tension by telescoping of the femoral stalk is a common method; however, the influence of anesthetic relaxation of the patient makes this somewhat unreliable.

The most common mechanism of dislocation is impingement. Osteophytes on both the acetabular or femoral side, capsular tissue, or scar tissue can cause a dislocation displacing the head to posterior or anterior. The femur becomes proximalized by the force of the abductors and adductors. This might also be called positional dislocation because the patient moves the leg into an insecure position, exterior of the safe range for a total hip replacement, especially during the first calendar month afterward implantation.

Technical errors such as malpositioning of the components are noted to be a common cause of dislocation [ane, 5, 9–11]. High inclination of the acetabular component (acetabular abduction angle) of more than than 60° can reduce superior coverage of the prosthetic head, whereas inclination below 30° tin atomic number 82 to lateral impingement in abduction and flexion. A retroverted or neutral cup does not provide stability when the patient is sitting or flexing the hip predisposing to posterior dislocation. Increased anteversion of the socket makes information technology possible to impinge at the posterior margin resulting in anterior dislocation. The effect of orientation of the acetabular component in correlation with dislocation is discussed in recent papers [i, 12]. The version of the femoral component (antetorsion) is also an of import cistron for proper hip stability. Over-antetorsion can lead to posterior impingement and anterior instability, and retrotorsion tin can lead to anterior impingement and posterior instability.

Neuromuscular disorders with pathologically increased musculus tension such every bit Parkinson's disease, cognitive palsy, and epilepsy represent a higher risk for dislocation afterward THA [3•, 13]. Surgeons must be mindful of these disorders when considering patients for hip replacement and may consequently consider the use of a constrained coupling mechanism or a dual mobility blueprint of socket. Some other reason for dislocation can be any traumatic displacement [iii•] of the hip with or without associated fracture. Excessive alcohol consumption or extreme obesity may facilitate this condition.

In developmental dysplasia of the hip (DDH), the beefcake and biomechanics of the hip are dissimilar from the normal hip. Shortening of the iliopsoas tendon, weakness of the gluteus medius muscle, and the anatomical position of the greater trochanter are factors that may cause dislocation fifty-fifty after proper positioning of the implants.

In a recent study, Hailer et al. stated that after analyzing more than 70,000 hip implantations in Kingdom of norway, patients with femoral cervix fracture or osteonecrosis of the femoral head are at a higher risk of dislocation [3•]. Employ of the minimally invasive and posterior approaches as well increases this take chances.

In revision surgery, there are multiple factors influencing the stability of the hip. Scar tissue formation, weakness of the gluteal muscles including palsy of the gluteus medius, the demand for resection of the proximal femur, or bone defect of the greater trochanter are atmospheric condition to deal with, representing a surgical challenge in club to avert postoperative dislocation. Use of larger head diameters (36 or forty mm) is suggested to lower the risk [6, nine, 14, fifteen].

Position of the implants

The 'rubber zone' of the acetabular component was described by Lewinnek with 40° of inclination and 15° of anteversion ±x°. It has been shown that values outside this range take a higher run a risk for implant dislocation to occur [16].

Increased cup inclination, leads to a more than "open" socket position, thus the cranial buttress for the femoral head might be less sufficient—less offset stability is given and the femoral head is more likely to lever the liner to superior. The maximum safe inclination is dependent on the loving cup pattern, simply more than than 60° has been shown to exist related to increased dislocation rates. Intraoperative anatomical landmarks, that might be used are the inductive inferior iliac spine and the incisura of acetabulum, an imaginary line between these 2 structures has an angle of xl°–45° to the horizontal axis, if anatomy is normal [ane, 12].

Anteversion follows the natural position of the acetabulum, represented by the transverse acetabular ligament [17]. Less anteversion means less stability when the patient is sitting and adducting the leg while internally rotating; this occurs quite oft in daily life. When a posterior approach is used, meticulous attention is required to achieve correct anteversion in gild to avoid posterior dislocation. Similarly, using an anterior approach, extensive anteversion should be avoided to reduce the take chances of anterior dislocation [i].

The antetorsion of the stalk has to follow the natural rotation of the proximal femur of approximately xv° ± v° to the transepicondylar axis of the knee. The proper alignment of the stem is oftentimes not a surgical claiming, therefore, relatively rarely seen as a mayor reason of dislocation.

The most important aspect is the 'combined anteversion' of the implants. In THA combined anteversion (ie, the sum of cup anteversion and stem antetorsion) are used equally parameters to assess the appropriateness of overall prosthetic alignment [5, 10, eleven, 18]. Intraoperatively, an "equator test" can exist performed as suggested past Ranawat and the phenomenon is observed when the leg is in neutral position (the hip is fully extended) and 45° internally rotated: if the head is observed to be coplanar with the socket so the combined anteversion is 45° [8].

Widmer has defined a 'mathematic' recommendation for positioning of the components [18]; the articulating hemispheric surface of the acetabular cup should be oriented between 40°–45° of radiographic inclination, betwixt xx°–28° of anteversion (AV), and should be combined with stalk antetorsion so that the sum of loving cup anteversion plus 0.7 times the stalk antetorsion (AT) equals 37° [AV + 0.7AT = 37°].

Head diameter

Smaller head diameters (22–28 mm) tend to accept optimal vesture characteristics but are more likely to dislocate [two]. Caput sizes above 28 mm are considered to be safer because of a favorable head-neck ratio and a larger "jump altitude." At primary THA, larger head diameters (28–32 mm) are widely used. In acetabular cup sizes beyond 56 mm, head diameter of 36 mm is recommended by some authors [14]. In revision cases, head diameters of 36–xl mm may be used to reduce the adventure of dislocation [15]. Larger caput sizes are associated with a lower dislocation run a risk, all the same, the potential for greater polyethylene article of clothing secondary to the increased sliding altitude must exist considered [19•].

Dislocation handling

Closed reduction

Dislocation of THA is a painful condition; patients are usually unable to walk. Closed reduction is carried out as soon as possible afterwards diagnosis to avert neurologic injury [20]. Optimally, general anesthesia and fluoroscopy are required, and commonly, 2 surgeons are required to safely perform the reduction maneuver [21]. Before the process, the mechanism and reason for dislocation should be analyzed. The diverse methods of closed reduction are described below [22–25].

Anterior dislocation

To reduce an inductive dislocation the pelvis is stabilized by two hands of 1 surgeon on the fluoroscopy tabular array or bed, while the second surgeon pulls the dislocated leg forth the longitudinal axis and rotates internally. The prosthetic head than returns into the acetabular liner.

Posterior dislocation

To reduce a posterior dislocation the pelvis is similarly stabilized by 2 hands, the surgeon holds the adducted and internally rotated thigh and the hip is flexed above 90°. Then the surgeon brings the femoral head near the posteroinferior rim of the acetabulum while traction is maintained, and the prosthetic head is levered into the liner by abduction, external rotation, and extension of hip (Bigelow's maneuver [24]). A snap is usually felt by the person stabilizing the pelvis.

Another technique for reducing a posterior dislocation is described in the Rochester Method [24] or Tulsa Technique [26]. The patient is placed supine with the uninjured hip and knee flexed. 1 of the surgeon'due south hands is placed underneath the injured genu and over summit of the uninjured knee; this knee acts equally a pivot point for the surgeon'south hand. The patient's injured hip and knee are flexed, the other mitt of the surgeon grabs the ankle of the injured side and applies gradually traction, and at the same time, the ankle can be used to rotate the hip.

Open reduction

If airtight reduction fails or re-dislocation occurs inside several days subsequently the reduction, open reduction is to be considered [27]. Earlier surgery, all possible reason(s) for the dislocation should be identified and the proper handling option should be chosen. If dislocation with massive hematoma formation and/or palsy of the femoral or sciatic nerve occurs, open up reduction is mandatory within several hours. At open surgery, the fluid or hematoma is removed to decrease the joint tension. The membrane in and around the joint is debrided to encourage the soft tissues to class a new pseudocapsule which provides more than stability. A posterior soft tissue repair is considered and carried out if possible to prevent the articulation from re-dislocating. Possible surgical treatment options are listed in Figs.ane and ​ 2, TableI.

A + B. Patient with massive osteolysis of the correct proximal femur with modular THA (A). Due to recurrent dislocation constrained acetabular liner was inserted to attain stability (B).

A+ B. Patient with recurrent dislocation: measurements (A) reveal a decreased offset right (156 mm) vs left (163 mm) site. The inclination of the cup was 53°, within the safe zone. At open reduction (B) a retainment ring and an offset head were implanted for correction.

Table I

Possible surgical treatment options at dislocation of THA

Reason for Dislocation	Handling choice
Shortening, laxity	Head substitution (consider starting time head)
Anteversion low	Dorsal retainment ring
Cup inclination loftier	Cranial retainment ring or cup substitution
Cup in retroversion	Loving cup exchange
Anterior impingement	Remove osteophytes and scar tissue, longer head
Anteversion high	Cup exchange or beginning caput
Loving cup horizontal, impingement in flexion	Loving cup exchange
Multidirectional instability	Bipolar hypermobility loving cup or constrained cup with head exchange
Deficient abductors	Constrained cup or bipolar hypermobility cup

Prevention of dislocation

The all-time option to 'care for' THA dislocation is to preclude the occurrence in the first instance [7]. Using a posterior approach, the general repair of the posterior structures capsule and external rotators (piriformis tendon) with nonabsorbable sutures is a valuable option simply non e'er possible to behave out. At final reduction, with the trial heads one should perform the dislocation tests, the equator exam, and check for telescoping of the components. Appropriate head size and length are to be chosen. In case of instability, a retainment ring tin can provide more stability and can exist a good option. In addition, almost implant companies now offer lipped (ie, dorsal rim) poly-liner options. At preoperative planning, the center of rotation should exist determined and during the surgery restored to fulfill the biomechanical environment of the hip. After implantation of THA in early postoperative period, abduction cushions may be used to prevent the patient from adducting the operated leg.

In case of revisions with loss of the greater trochanter or insufficient gluteus medius, or after resection of the proximal femur (eg, in septic surgery) a dual mobility cup [28] or a constrained loving cup [6] should be considered. The dual mobility loving cup consists of a metallic crush that encloses a movable polyethylene liner. The femoral caput (bore 22 or 28 mm) is encased by the hemispheric liner so that it also allows rotation of the femoral caput within the polyethylene sphere. The polyethylene casing tin can articulate partly against the metal casing and partly against the femoral head fixed on the stalk. The concept differentiates from the constrained liner used for uncemented cups. In this implant, the insert is rigidly fixed to the metallic beat while the liner in the dual mobility cup can likewise clear with the metallic crush. From a biomechanical perspective, a dual mobility system should take advantages compared with a constrained liner considering extreme movements are not translated to a shear force at the cup-bone interface [six, 28].

Patient teaching

Earlier primary THA, patients should exist educated equally to what range of motion is to exist expected subsequently the implantation and what movements and actions are to be avoided to prevent dislocation, particularly in the early on postoperative stage. Adduction and internal rotation afterward posterior approach is avoided for at least 3 months. Later anterior approach adduction, external rotation and hyperextension are avoided for 6–12 weeks. In both cases, patient should refrain from deep sitting with the hips flexed above ninety°.

Post-dislocation treatment

After closed reduction, 24 hours of rest is recommended, followed past gradual mobilization nether the supervision of a physiotherapist. Normally, total weight bearing can be allowed, unless the soft tissues are painful. Crutches are normally required. In recurrent cases or in not-compliant patients, a brace can exist practical with restriction of the range of motion of the injured hip. Adduction, flexion over 90°, and rotation of the hip is express by the brace for 6 weeks. Then, gradually increment each motion modality, just adduction and internal rotation should be avoided for 3 months. After this period of fourth dimension, strengthening of the pelvicrural muscles, especially the gluteal muscles, tin can be emphasized. Home trainer and pond are advantageous for muscle training, of grade under the guidance of a trained physiotherapist.

Conclusions

Dislocation remains a mayor complication after THA. While multiple reasons may be contributing factors leading to dislocation, a precise identification of the exact reason is of major importance, to program for a proper surgical or non-surgical correction. Based on the identified pathology, in most cases a closed reduction can be performed. Operative revision scenarios are based near oftentimes on the achieved implant orientation or soft tissue laxity subsequently chief implantation.

Compliance with Ideals Guidelines

Disharmonize of Interest

Akos Zahar declares that he has no disharmonize of interest. Amit Rastogi declares that he has no conflict of involvement. Daniel Kendoff declares that he has no conflict of interest.

Human and Animal Rights and Informed Consent

This article does non incorporate any studies with human or animal subjects performed past any of the authors.

References

Papers of detail involvement, published recently, have been highlighted as: • Of importance

ane. Biedermann R, Tonin A, Krismer K, Rachbauer F, Eibl G, Stöckl B. Reducing the gamble of dislocation after total hip arthroplasty: the event of orientation of the acetabular component. J Os Articulation Surg Br. 2005;87:762–9. [PubMed] [Google Scholar]

ii. Swedish Hip Arthroplasty Annals, Annual Report 2011, http://www.shpr.se.

3. Hailer NP, Weiss RJ, Stark A, Kärrholm J. The risk of revision due to dislocation after full hip arthroplasty depends on surgical approach, femoral head size, sex, and primary diagnosis. An assay of 78,098 operations in the Swedish Hip Arthroplasty Register. Acta Orthop. 2012;83:442–8. doi: 10.3109/17453674.2012.733919. [PMC free article] [PubMed] [CrossRef] [Google Scholar]

four. Devane PA, Wraighte PJ, Ong DC, Horne JG. Practise joint registries report true rates of hip dislocation? Clin Orthop Relat Res. 2012;470:3003–6. doi: ten.1007/s11999-012-2323-6. [PMC gratuitous commodity] [PubMed] [CrossRef] [Google Scholar]

5. Moskal JT, Capps SG. Acetabular component positioning in total hip arthroplasty: an prove-based analysis. J Arthroplasty. 2011;26:1432–7. doi: x.1016/j.arth.2010.11.011. [PubMed] [CrossRef] [Google Scholar]

6. Sikes CV, Lai LP, Schreiber Thou, Mont MA, Jinnah RH, Seyler TM. Instability subsequently full hip arthroplasty: handling with large femoral heads vs constrained liners. J Arthroplasty. 2008;23(vii Suppl):59–63. doi: 10.1016/j.arth.2008.06.032. [PubMed] [CrossRef] [Google Scholar]

7. Patel PD, Potts A, Froimson MI. The dislocating hip arthroplasty: prevention and handling. J Arthroplasty. 2007;22(4 Suppl ane):86–xc. doi: ten.1016/j.arth.2006.12.111. [PubMed] [CrossRef] [Google Scholar]

viii. Ranawat CS, Rao RR, Rodriguez JA, Bhende HS. Correction of limb-length inequality during total hip arthroplasty. J Arthroplasty. 2001;16:715–20. doi: 10.1054/arth.2001.24442. [PubMed] [CrossRef] [Google Scholar]

9. Amstutz HC, Le Duff MJ, Beaule PE. Prevention and treatment of dislocation afterward total hip replacement using big diameter balls. Clin Orthop Relat Res. 2004;108. [PubMed]

x. Amuwa C, Dorr LD. The combined anteversion technique for acetabular component anteversion. J Arthroplasty. 2008;23:1068. doi: 10.1016/j.arth.2008.04.025. [PubMed] [CrossRef] [Google Scholar]

eleven. Fukunishi S, Fukui T, Nishio Due south, Fujihara Y, Okahisa South, Yoshiya S. Combined anteversion of the full hip arthroplasty implanted with image-complimentary cup navigation and without stem navigation. Orthop Rev. 2012;4:e33. doi: 10.4081/or.2012.e33. [PMC free article] [PubMed] [CrossRef] [Google Scholar]

12. Meftah Chiliad, Yadav A, Wong Ac, Ranawat Every bit, Ranawat CS. A novel method for accurate and reproducible functional cup positioning in total hip arthroplasty. J Arthroplasty. 2013;28:1200–5. doi: 10.1016/j.arth.2012.09.018. [PubMed] [CrossRef] [Google Scholar]

thirteen. Queally JM, Abdulkarim A, Mulhall KJ. Total hip replacement in patients with neurological conditions. J Bone Joint Surg Br. 2009;91:1267–73. [PubMed] [Google Scholar]

14. Peters CL, McPherson E, Jackson JD, et al. Reduction in early dislocation charge per unit with large-diameter femoral heads in primary total hip arthroplasty. J Arthroplasty. 2007;22(6 Suppl 2):140. doi: 10.1016/j.arth.2007.04.019. [PubMed] [CrossRef] [Google Scholar]

fifteen. Rodriguez JA, Rathod PA. Big diameter heads: is bigger always meliorate? J Bone Joint Surg Br. 2012;94(11 Suppl A):52–4. [PubMed] [Google Scholar]

16. Lewinnek GE, Lewis JL, Tarr R, Compere CL, Zimmerman JR. Dislocations after full hip-replacement arthroplasties. J Bone Joint Surg Am. 1978;60:217–20. [PubMed] [Google Scholar]

17. Archbold HAP, Mockford B, Molloy D, et al. The transverse acetabular ligament, an aid to acetabular component placement during total hip arthroplasty. J Bone Joint Surg Br. 2006;88:883. [PubMed] [Google Scholar]

18. Widmer KH, Zurfluh B. Compliant positioning of full hip components for optimal range of motility. J Orthop Res. 2004;22:815–21. doi: 10.1016/j.orthres.2003.11.001. [PubMed] [CrossRef] [Google Scholar]

xix. Garbuz DS, Masri BA, Duncan CP, Greidanus NV, Bohm ER, Petrak MJ, et al. The Frank Stinchfield Honour: dislocation in revision THA: practise large heads (36 and 40 mm) result in reduced dislocation rates in a randomized clinical trial? Clin Orthop Relat Res. 2012;470:351–6. doi: 10.1007/s11999-011-2146-ten. [PMC free article] [PubMed] [CrossRef] [Google Scholar]

20. Gaines RJ, Hardenbrook M. Closed reduction of a confused full hip arthroplasty with a constrained acetabular component. Am J Orthop. 2009;38:523–5. [PubMed] [Google Scholar]

21. Schafer SJ, Anglen JO. The East Baltimore Lift: a simple and effective method for reduction of posterior hip dislocations. J Orthop Trauma. 1999;xiii:56–vii. doi: 10.1097/00005131-199901000-00013. [PubMed] [CrossRef] [Google Scholar]

22. Amstutz HC, Kody MH. Dislocation and subluxation. In Amstutz HC, editor. Hip arthroplasty. Churchill Livingstone, New York; 1991.

23. DeLee JC. Fracture and dislocation of the hip. In Rockwood CA, Greenish DP, Bucholz RW, editors. Fractures in adults. iii^rd edition. JB Lippincott, Philadelphia; 1991.

24. Wheeless CR. Dislocations and fracture dislocations of the hip. In: Wheeless' Textbook of Orthopaedics (on line), www.wheelessonline.com.

25. Skoff HD. Posterior hip dislocation, a new technique for reduction. Orthop Rev. 1986;15:405–9. [PubMed] [Google Scholar]

26. Vosburgh CL, Vosburgh JB. Closed reduction for full hip arthroplasty dislocation. The Tulsa Technique. J Arthroplasty. 1995;10:693–4. doi: 10.1016/S0883-5403(05)80218-ix. [PubMed] [CrossRef] [Google Scholar]

27. Bourne RB, Mehin R. The dislocating hip: what to practise, what to do. J Arthroplasty. 2004;19(iv Suppl one):111–4. doi: 10.1016/j.arth.2004.02.016. [PubMed] [CrossRef] [Google Scholar]

28. Grazioli A, Ek ET, Rüdiger HA. Biomechanical concept and clinical outcome of dual mobility cups. Int Orthop. 2012;36:2411–8. doi: ten.1007/s00264-012-1678-3. [PMC free commodity] [PubMed] [CrossRef] [Google Scholar]

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Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4094102/

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