Management of Dislocated Total Hip Replacement caused by Soft Tissue Imbalance
Mustafa Mohamed Mustafa Eljiru1,Yousef Mohamed Mohamed Khaira 2,Reda Hussein Elkady3,and Mohamed Ismael Abdelrhman Kotb 4
1M.B; B.Ch.; Faculty of Medicine,Azzawia University, Libya.
2Professor of Orthopedic Surgery,Faculty of MedicineZagazigUniversity.
3Assistant Professor of Orthopedic Surgery,Faculty of Medicine Zagazig University.
4Lecturer of Orthopedic Surgery, Faculty of Medicine Zagazig University.
Correspondingauthor:Mustafa Mohamed Mustafa Eljiru Email:[email protected]
Abstract
Background:With the improvement of the surgical techniques and prosthesis design, the rate of dislocation after total hip arthroplasty (THA) has decreased to 0.05-3.9%. The dislocations of THA are not only related to soft tissue tension but also related to the basic situation of patients, surgeon’s operation, surgical methods, hip prosthesis design, and prosthesis placement.
Aim of the study: To evaluate the functional outcome and importance of soft tissue reconstruction in total hip dislocations.
Patients and methods:The current prospective and retrospective cohort study was carried in Orthopedic Department, Zagazig University Hospitalsin Egypt and Misurata central hospital in Libya on 18 Patient with post recurrent THR dislocation caused by soft tissue defect underwent dislocated total hip arthroplasty to evaluates the functional outcome and importance of soft tissue reconstruction in total hip dislocations.
Results:Femur head size in 1ry total Hip Replacement for studied patients ranged from 28 to 36 mm (77.7% by 36mm). 66.7 % of patients complaint from dislocation after 2nd month after Total Hip Replacement caused by Soft Tissue Imbalance, while 33.3% third at second months. 16 (77.8%) of patients free from complication, while 2(11.1%) of patients came with Superficial infection post operatively. The main procedure was applied to manage dislocated THR caused by Soft Tissue Imbalance was increase neck length with enhanced soft tissue repair and bracing for 44.4% of patients, 33.3% were treated with only enhanced soft tissue reconstruction and restore tension with bracing, and greater trochanteric advancement with soft tissue reconstruction and bracing in 22.2% of patients. There was a statistically significant increase in points of all parameters postoperative.All patients had pre-operative Harris poor grade, with mean 21.9±9.8 and range from 10 to 38. While postoperative Harris grade for studied group was 33.3% fair 44.4% good and 22.2 % of them had excellent Harris grade. with mean 82±8.27 and range from 70 to 94 with difference statistically significance.
Conclusion:THR is one of most successful surgery, rare cases of replacement may complaining from early or late complications, dislocation is one of these complications, one cause of dislocation is soft tissue imbalance and not good repair and restoring tension.
Keywords:Total Hip Replacement (THR), Soft tissue imbalance.
1. Introduction
The rate of dislocation of primary hip replacements ranges from 0.2% to 10%, while that of artificial hip joints that have already been surgically revised can be as high as 28%1. The risk of dislocation is greatest in the first12 weeks after hip arthroplasty with approximately 60% to70 % occurring during the first six weeks (1).
With the improvement of the surgical techniques and prosthesis design, the rate of dislocation after total hip arthroplasty (THA) has decreased to 0.05-3.9%, according to the recent reports.
Nevertheless, postoperative dislocation is still the most common early complication after THA and one of the most common causes of early revision of primary THA (2).
Dislocation after total hip arthroplasty is painful, prolongs the hospitalization period, and the patient requires the use of a brace and frequently requires a second operative procedure (3).
The posterior approach, the most popular approach, is technically simpler than other approaches, but it reportedly has an increased risk of postoperative dislocation. The posterior approach causes disruption of the posterior capsule and the short external rotators. The role of posterior soft tissue repair in reducing dislocation has been studied (3).
Many surgical approaches for total hip arthroplasty (THA) aim to maximize capsule preservation and/or repair capsule incisions, while others excise the capsule to improve exposure, as it is considered of little consequence. Capsule preservation and repair can help to lower dislocation rates, and may also maintain the defenses of the native hip against hypermobility, impingement, subluxation, and edge-loading (4).
To reduce the incidence of dislocation of THR, a good surgical repair of a soft tissue either posterior capsule and the lateral rotators in posterior approach or anterior capsule and hip abductors in lateral approach will reduce significantly the incidence of dislocation(5).
Closed treatment for a first-time dislocation is usually successful in two-thirds of cases. Bracing continued for 3-4 months following closed reduction for recurrent dislocation has been suggested.
Surgical management is necessary for those patients with persistent instability following non-operative management and reoperation rates of 31-44% have been reported (6).
The dislocations of THA are not only related to soft tissue tension but also related to the basic situation of patients, surgeon’s operation, surgical methods, hip prosthesis design, and prosthesis placement (7).
We aimed in our study to evaluate the functional outcome and importance of soft tissue reconstruction in total hip dislocations.
2. Patients and Methods A) Technical design:
(1) Setting of the study:
Zagazig University Hospitals in Egypt and Misurata central hospital in Libya.
(2) Design:
It is retrospective and prospective cohort study.
(3) Sample size:
As number of cases reporting dislocation of total hip arthroplasty not exceed 3 per months and in 6 months maximally reach 18. So, sample size is calculated compensatory to include all patient with dislocated of total hip arthroplasty in 6 months to be 18 cases.
(4) Method of patient collection:
(a) Inclusion criteria:
Patients aged between25-70 years, Patients post THR dislocation caused by soft tissue imbalance, and who had more than two times dislocation.
(b) Exclusion criteria:
Patients with first or second time of dislocation, patient unfit for surgery, neuromuscular patient, and other cause of total hip dislocation than soft tissue imbalance.
(B) Operational design:
The cases have been selected from orthopedic department in Zagazig University Hospital and Misurata Central Hospital.All cases underwent dislocated total hip arthroplasty.
Preoperative assessment:
The patients were admitted where the following measures were undertaken:
a) Clinical evaluation:
1) History taking this included:
Personal data: name, age, sex, occupation.
Mechanism of dislocation by Ask how the dislocation occurred. Elucidating how the current dislocation occurred, or the activity that was being performed in relation to the position of the affected limb.
Medical history as diabetic mellitus (DM), hypertension, bronchial asthma, or stroke or any neuromuscular problem.
An inquiry into other potential previous episodes of instability or dislocation is of paramount importance.
Questions regarding the presence of infectious symptoms such as fevers, chills, antecedent pain or night sweats are also important.
A review of previous documentation, including operative notes documenting what approach was used, types and positioning of implants, as well as any noted intra- or post-operative complications is vital
2) Physical examination includes:
General assessment:
Assessment of both lower extremities, carefully noting gait, range of motion, strength (paying close attention to the abductor musculature), neurovascular status, leg length, location of previous incisions and leg position on presentation. This was done to assess the general fitness to surgery, and to identify any potential source of infection.
Local examination:
The skin and soft tissue condition around the hip joint
Leg length discrepancy
Presence of deformity B) Radiographic evaluation:
1. X-ray:
Anteroposterior radiographs of the pelvis and both hips were taken for all the patients, and lateral X-ray plain of the affected hip to assist femoral and acetabular component position and also to exclude other cause of dislocation and we were assisting of:
• Head to neck ratio.
• Loosening,
• Neck length and offset.
• Angulation and Any evidence of subsidence.
2. CT
To assessment of the acetabular and femoral orientation and version. Is difficult to ascertain from plain radiographs of the hip as well. So, we used both computed tomography scans and plain radiographs to assist acetabular and femoral version.
C)Routine Clinical investigations: These include:
Additionally, if clinically indicated, diagnostic tests including:
• CBC,
• LFT and RFT,
• ESR, CRP,
• HIV, HCV, HBV,
• PT, PTT, INR.
Treatment of dislocated THA caused by soft tissue:
(A)Initialy management of a dislocated THA by Closed Reduction with bracing:
All patients received good anesthesia and muscle relaxant.Patients were on supine position.
Technique:
To reduce anterior dislocation in general we have to do traction, adduction and gentle internal rotation. posterior dislocation reduction is usually by traction, abduction and external rotation. The majority of repositions through simply pulling on the leg succeed well; in rare cases the ball may get firmly stuck in tissues around the hip and cannot be moved by pulling applied on the leg.
After reposition of the dislocated total hip, we control the nerve function and circulation in the leg, because dislocation may damage the nerves or the vessels crossing the dislocated hip joint (the inferior gluteal artery, the deep femoral artery and its branches.
After reduction the surgeon takes X-ray control pictures to verify that the ball is in place again and to verify that the total hip joint was not damaged by dislocation or reduction. When X-ray control verified that the reposition succeeded the patient's leg is placed in brace. The method of bracing the leg and the length of bracing vary from days to weeks.
Then treatment with external bracing often results in good outcomes. However, the use of braces is extremely patient-dependent, as the braces are inconvenient and cumbersome. Even the most compliant patients will have difficulty using braces effectively, making them challenging to study in large numbers or to implement effectively on a regular basis.
We used of brace after determine direction of dislocation (anterior or posterior) and times of dislocation:
• First dislocation: Brace for 6 weeks
* Posterior, range of motion 0° to 60°, 15° abduction
* Anterior, range of motion -30° to 90°, neutral abduction/adduction
• Second dislocation: brace for 3 months
• Third dislocation: for surgical intervention
(B) Operative management:
Surgical indications and management In patients who have a recurrent instability more than two times dislocation, and who have failed conservative management, Surgical options for the treatment of instability or recurrent dislocation that caused by soft tissue imbalance that used in our study include:
- Enhanced soft tissue reconstruction.
- Advancement of the greater trochanter.
- Increase neck length.
Enhanced soft tissue repair:
Surgical Technique
- Anaesthesia: spinal or general - Positioning: lateral decubitus.
- Approach: same previous approach.
- Incision: at the same previous incision, incision length 10-15 cm is adequate.
-Dissection:
After remove the old surgical scar. The fat and underlying deep fascia were sharply dissected till ilio tibial band.
Incision of the band and we cut the adhesion of abductor muscles in one thick flap with extension to vastus lateralis.
Reduction of the prosthesis (if not reduced closely) and we checked hip stability, Hip stability checked in flexion and internal rotation and abduction (to test posterior stability), extension and external rotation rotation (to test anterior stability), and in the position of sleep (adduction, partial flexion, and mild internal rotation). In each position any tendency toward instability or prosthetic or bony impingement should be identified and corrected.
After telescoping and another intra-operative hip stability test were done. The restoring soft tissue imbalance were done by.
- 8 cases by increase neck length (medial offset), other cases were had the largest neck length.
- 6 cases by enhanced soft tissue repair only, by sutured the anterior flap of muscle fibers of the gluteus medius and vastuslateralis to the posterior flap of muscle fibers or posterior tendinous cuff by heavy absorbable suture.
- After closure the abductors, 4 cases we need to do greater trochanteric advancement to increase tension and restore balance of abductors.
After good repair to soft tissue and restoring the abductors balance that surrounded the joint. The wound and the hip joint are irrigated thoroughly, a suction drain was utilized, Then the subcutaneous tissue is closed with absorbable suture and the skin is closed with skin staples or suture
Postoperative management:
Transfer of the patient:
The patient was directly transferred from the operating room to the bed with the hips kept in abduction brace.
Medications:
Antibiotics: all patients received intravenous third generation cephalosporin for three days postoperatively followed by oral antibiotics for one week.
Analgesia: postoperative pain was controlled in the first 48 hours using intravenous analgesic then mild analgesics belonging to NSAIDs were given as required for one week.
Anticoagulants: All patients received anticoagulant postoperatively.
Exercises:
Quadriceps exercises in bed and active knee, ankle and foot movements were started from second day.
Care of suction drain:
The suction was inspected regularly, and the amount of blood was measured and the tubes were removed in the third postoperative day and in three patients we kept drain for one week.
Follow up:
Clinical follow up: By clinical evaluation (Harris Hip Score was used for clinical evaluation of patients) and standard radiographs were made for all patients at subsequent follow up at two weeks after operation, 6-week,3 months, 6 months.
Care of the wound:
New dressing was applied in the 3rd postoperative day with removal of the suction drain then the wound condition was followed during the first 2 weeks after which the stitches were removed.
Ambulation protocol:
Protective weight bearing with crutches in the first month, then started with walking frame for another one month, then patients were allowed to bear weight as tolerated with the aid of one crutch then full weight bearing after 3 months.
Statistical Analysis:
All data were collected, tabulated and statistically analyzed using SPSS 20.0 for windows (SPSS Inc., Chicago, IL, USA 2011)). Quantitative data were expressed as the mean ± SD &median (range), and qualitative data were expressed as absolute frequencies (number)& relative frequencies (percentage).
3. Results:
72.2% of studied patients were females, 27.8% males, their age ranged from 30 to 64 years with mean± SD 55.7 ±9.9 (Table 1). All patients (100%) dislocation due to soft tissue imbalance as complication of primary Total Hip Replacement (table 2).
Two third of patients complaint from dislocation more than 2nd month after Total Hip Replacement caused by Soft Tissue Imbalance, while other third at second months (Table 3).14 (88.8%) of patients free from complication, while 2 (11.2%) of patients complained from Superficial infection postoperative (Table 4). The main procedure was applied to manage Dislocated Total Hip Replacement caused by Soft Tissue Imbalance was increase neck length + enhanced soft tissue repair with bracing for 44.4% of patients, 33.3% treated with soft tissue reconstruction and restore tension with bracing, and 22.2% of patients greater treated with trochanteric advancement + soft tissue reconstruction and bracing (Table 5).
A statistically significant increase in points of all parameters postoperative. Mean of pain score improved from marked pain (10.1±8.26) to slight pain (38.7±5.04) post- operative. Mean Walk score improved from (1.1±1.02) pre-operative to (9.3±1.53). post- operative. Mean of Support score improved from (1.9±1.1) pre-operative to post- operative (7.8±2.39). Limping improved from moderate limping (2.2±2.6) pre-operative to (9±1.45) post- operative. Mean Climbing upstairs score in most cases improved from (0.55±0.51) pre-operative to (1.9±0.32) post- operative (Table 6).
A statistically significant increase in points of all parameters postoperative. Wear Shoes stocks score improved from (2±0) to (3.1±1.02) post- operative. sitting improved from (1.6±1.53) to sit comfortably to any chair for one hours (4.3±0.97) postoperative. mean of uses public transportation increased to be postoperative 0.78±0.43 and deformity improved to be 3.1±0.58.
Range motion improved to do normal motion range post- operative (Table 7).
Table (1): Socio demographic of studied patients ((n=18):
Items Age per years
Mean ±SD (range)
55.7 ±9.9 (30-64) Sex(no.%)
Females Males
13 5
72.2%
27.8%
Table (2): Cause of recurrent dislocation (n.18).
Items No. %
Cause of dislocation soft tissue imbalance
18 100.
0 Complication primary Total Hip Replacement
Dislocation
18 100.
0
Table (3): Time of 3rd time of dislocation
Time Of Dislocation Frequency Percent
3rd time of dislocation
2nd month 6 33.3
more than 2nd month 12 66.7
Total 18 100.0
Table (4): Frequency distribution of postoperative reconstruction complications
postoperative complications Frequency Percent
postoperative compilations
Superficial infection 2 11.2
No complication 16 88.8
Total 18 100.0
Table (5): Procedure which used to restore of soft tissue balance
Procedure of Redislocation Frequency Percent
Procedure of Redislocation enhanced soft tissue reconstruction and restore tension+
brace 6 33.3
greater trochanteric advancement + soft tissue
reconstruction+ brace 4 22.2
increase neck length + enhanced soft tissue repair+ brace 8 44.4
Total 18 100.0
Table (6): Comparison of parameters of Harris score pre and postoperative for studied group
Parameter s
Harris, score
W p-
value Preoperativ
e
Postoperativ e Pain
Mean± SD Median (range)
10.1±8.26 0-20
38.7±5.04 30-44
3.7 7
0.000 1 (S) Walked
Mean± SD Median (range)
1.1±1.02 0-2
9.3±1.53 8-11
3.7 6
0.000 1 (S) Support
Mean± SD Median (range)
1.9±1.1 0-3
7.8±2.39 5-11
3.7 4
0.000 1 (S) Limp
Mean± SD Median (range)
2.2±2.6 0-5
9±1.45 8-11
3.7 8
0.000 1 (S)
Table(7): Rest of comparison of parameters of Harris score pre and postoperative for studied group
Parameters Harris, score
W P
Preoperative Postoperative Shoes stocks
Mean± SD Median (range)
2±0 2-2
3.1±1.02 2-4
3.16 0.002
Sitting Mean± SD
Median (range)
1.6±1.53 0-3
4.3±0.97 3-5
3.82
0.000 1 (S) Transportation
Mean± SD Median
(range)
0.33±0.48 0-1
0.78±0.43 0-1
2.31 0.021
Deformity Mean± SD Median
(range)
0.88±0.9 0-2
3.1±0.58 2-4
3.77
0.000 1 (S)
Range motion Mean± SD
(range)
1.1±0.76 0-2
3.9±0.58 3-5
3.78 2
0.000 1 (S)
4. Discussion
The dislocation in THR that caused by soft tissue imbalance occurs mainly within the first 3 months following primary total hip replacement (8). This scenario occurs when the patient reaches the extremes of the prosthetic range of motion and the femoral neck levers on the acetabular cup, allowing the femoral head to escape from the acetabulum. Also, laxity or soft-tissue incompetence surrounding the hip joint are common conditions that can lead to postoperative dislocations (i.e., like post revision), and neuromuscular disorders (e.g., Parkinson disease). Predisposing factors for hip dislocations continue to rise (9).
Another study has reported dislocation that caused by soft tissue imbalance rates as high as 10%
from all causes of dislocation after primary procedures and up to 28% after revision, suggesting that the number of patients who present with dislocations may also increase (10).
The current study showed that 13 patients (72.2%) were females, and 5 patients (27.8%) were males, their age ranged from 30 to 64 years. which is nearly close to the results of Liu et al. (11) who reported that the mean age of patients was range from 27 to 75 years and there were 14 males (35.9%) and 25 females (64.1%)3. Also, Alwahbany et al. (11), reported that the mean age of
patients was range, 25-75 years and there were 10 females (37.04%) and 17 males (62.96%).
Leichtle et al., (12) reported that there were 68 dislocations soft tissue cause (75%) occurring within the first 1 months, 80 cases third dislocations soft tissue cause (88%) within the first 3 months after primary surgery and consequence of closed reduction. Only 11 dislocations caused by soft tissue (12%) occurred later than 3 months after surgery .
Ding et al., (13), reported that the first dislocation of the a total of 19 dislocations (86.4%) occurred within 6 months, and 3 patients more than 6 months postoperatively.
Gupta et al., (14) reported that Early complications noted were fairly less, infection was found in 4% cases which was superficial, hip dislocation was found in 2% of cases.
Kaplan and Robert Posset al(15)., demonstrated the benefit of trochanteric advancement for treatment of recurrent dislocation. The procedure was performed on 21 patients who had experienced an average of 3.9 dislocations (range, 2-8) in a mean period of 47 weeks after hip replacement (range, 2 weeks to 10 years), and excluded other causes of dislocation. Sixteen of the 21 patients (76%) had no further dislocations after trochanteric advancement. Five patients (24%) dislocated again.
Alwahbany et al., (16) who performedsoft tissue repair for 31 recurrent hip dislocation after posterior approach found 2 hips with deep infection and no reported hip dislocation.
Murray et al (17)., 502 patients who underwent revision were braced postoperatively, and 650 patients were not braced. The overall 90-day dislocation rate for all patients was 5.5%. The dislocation rate was 5.2% for the patients who were braced compared with 5.7% for the patients who were not braced. Of those that dislocated, 3.0% required re-revision for instability in the brace group and 4.9% in the non-bracegroup.
Ogawa, Takeshi, et al(7) in 52 patients, 18 hips in recurrent THA group and 34 hips in the stable THA group they found soft tissue tension is approximately 4-fold lower in patients exhibiting recurrent dislocations following THA with short neck and femoral offset than in exhibiting no dislocations and that femoral offset was related to decreased soft tissue tension. This indicates that increase soft tissue tension by increase neck length and offset is one of important factors related to prevention from recurrent dislocation.
Concerning the Harris parameters, the current study showed that statistically significant increase in points of all parameters postoperative. Mean of pain score improved from marked pain (10.1±8.26) to slight pain (38.7±5.04) post- operative. Mean Walk score improved from (1.1±1.02) pre-operative to (9.3±1.53). post- operative. Mean of upport score improved from (1.9±1.1) pre-operative to post- operative (7.8±2.39). Limping improved from moderate limping (2.2±2.6) pre-operative to (9±1.45) post- operative. Mean Climbing upstairs score in most cases improved from (0.55±0.51) pre-operative to (1.9±0.32) post- operative.
In agreement with the present study, the study of Taheriazam and Saeidinia (18) revealed thatHHS score improved from mean preoperative score of 44.93±8.40 (ranged 30–62) to 89.76±9.97 (ranged 45– 96) after 6 months follow-up. The mean of 12 months follow-up HHS score and final follow-up scores were 94.54±2.31 (ranged 90–98) and 95.41±2.27 (ranged 92–99) respectively. All of the differences between preoperative HHS score and its follow-ups were significantly improved (P=0.0001).
The current study showed that statistically significant increase in points of all parameters postoperative. Wear Shoes stocks score improved from (2±0) to (3.1±1.02) post- operative. sitting improved from (1.6±1.53) to sit comfortably to any chair for one hours (4.3±0.97) post- operative.
mean of uses public transportation increased to be postoperative 0.78±0.43 and deformity improved to be 3.1±0.58. Range motion improved to do normal motion range post- operative.
Moura, and Figueiredo (19) reported that he mean Harris Hip Score improved from 42.91 ± 14.59 preoperatively to 88.55 ± 4.50 postoperatively with a significant difference.
Purvance et al., (20) reported that the Harris Hip Score from improved from 48 preoperatively to 81 postoperatively with a significant difference and on follow up, the patient showed improved range of motion of hip joint without pain.
The current study showed that, all patients had pre-operative Harris poor grade, with mean 21.9±9.8 and range from 10 to 38. While postoperative Harris grade for studied group was 33.3%
fair 44.4% good and 22.2 % of them had excellent Harris grade. with mean 82±8.27and range from 70 to 94. difference statistically significant.
Alwahbany et al. (16) reported that he preoperative Harris hip score were poor (< 70) for all patients. But postoperatively, there were 19 patients (70%) were excellent (90%), 7 patients (26%) (80-89) and one patient (4%) was fair, with no poor results.
5. Conclusion
THR is one of most successful surgery, rare cases of replacement may complain from early or late complications, dislocation is one of these complications, one cause of dislocation is soft tissue imbalance and not good repair and restoring tension. The dislocations of THR also are not only related to soft tissue tension but also related to the basic situation of patients, surgical methods, surgeon’s experience, prosthesis placement and hip prosthesis design.
Prevention remains the best treatment. Third time or more than dislocation after THA that caused by soft tissue imbalance is difficult to treat and gives a major challenge to us. Although most cases we should be made to identify a predominant cause of imbalance, whose treatment will provide an optimal outcome. When the need for surgical treatment has been established based on a comprehensive evaluation of the instability, we must make sure that all the material needed is available and appropriate for the current prosthesis. Implant exchange is usually needed and is more often partial than complete.
The decision rests on the preoperative data and findings at revision surgery. Even when an apparent cause is identified, there should be no hesitation in combining several stabilizing procedures, such as use of a larger femoral head if allowed by the implants, increase of inadequate femoral offset, and enhanced soft tissue repair which should be performed routinely
6. Conflict of Interest: Noconflictofinterest.
7. References
1. Zhang. Y, Yang Tang & Chuncai Zhang &Xue Zhao & Yang Xie & (2013), Modified posterior soft tissue repair for the prevention of early postoperative dislocation in total hip arthroplasty. Int. Orthop. 37, 1039–1044.
2. Liu, Q., Cheng, X., Yan, D. & Zhou, Y. (2019)Plain radiography findings to predict
dislocation after total hip arthroplasty. J. Orthop. Transl. 18, 1–6.
3. Suh, K.T., Park, B.G. & Choi, Y. J. (2004) A Posterior Approach to Primary Total Hip Arthroplasty with Soft Tissue Repair. Clin. Orthop. Relat. Res. 162–167.
4. van Arkel, R.J., Ng, K. C.G., Muirhead-Allwood, S.K. & Jeffers, J.R.T (2018). Capsular Ligament Function After Total Hip Arthroplasty. J. Bone Joint Surg. Am. 100, e94.
5. Zhang, D.L. Chen, K. Peng, F. Xing, H. Wang , Z. Xiang (2015). Effectiveness and safety of the posterior approach with soft tissue repair for primary total hip arthroplasty: A meta- analysis. Orthop. Traumatol. Surg. Res. 101, 39–44.
6. Lu, Y., Xiao, H. & Xue, F (2019). Causes of and treatment options for dislocation following total hip arthroplasty (Review). Exp. Ther. Med. 1715–1722 doi:10.3892/etm.2019.7733.
7. Ogawa, T., Takao, M., Hamada, H., Sakai, T. & Sugano, N (2018). Soft tissue tension is four times lower in the unstable primary total hip arthroplasty. Int. Orthop. 42, 2059–2065.
8. Dargel, J., Oppermann, J., Brüggemann, G.P. & Eysel, P. (2014) Dislocation following total hip replacement. Deutsches Ärzteblatt International. Dtsch. Arztebl. Int. 111, 884–891.
9. Dawson-amoah, K., Raszewski, J., Duplantier, N. & Waddell, B. S. (2018). Dislocation of the total Hip: A Review of Types, Causes and Treatment. 242–252.
10. Kremers, H.M., Larson, D.R., Crowson, C.S., Kremers, W.K., Washington, R.E., Steiner, C.A., & Berry, D.J. (2015). Prevalence of total hip and knee replacement in the United States. The Journal of bone and joint surgery. American volume, 97(17), 1386.
11. Pop, T., Szymczyk, D., Majewska, J., Bejer, A., Baran, J., Bielecki, A., & Rusek, W.
(2018). The assessment of static balance in patients after total hip replacement in the period of 2-3 years after surgery. BioMed research international.
12. Leichtle, U.G., Leichtle, C.I., Taslaci, F., Reize, P. & Wuenschel, M (2013). Dislocation after total hip arthroplasty: risk factors and treatment options. Acta Orthop Traumatol Turc 47, 96–103.
13. Ding, Z.C., Zeng, W.N., Mou, P., Liang, Z.M., Wang, D., & Zhou, Z.K. (2020). Risk of dislocation after Total hip arthroplasty in patients with Crowe type IV developmental dysplasia of the hip. Orthopaedic surgery, 12(2), 589-600.
14. Gupta, S., Singh, P.K., Saoji, K., Deshpande, S. & Khan, S (2017). To study the clinical outcome of total hip Arthroplasty. Indian J. Orthop. 3, 350–355.
15. Kaplan, S.J., Thomas, W.H. & Poss, R. (1987). Trochanteric advancement for recurrent dislocation after total hip arthroplasty. J. Arthroplasty 2, 119–124.
16. Alwahbany, S.A.M., Elkadagri, M.H. & Hussien, A.D (2017).Dislocation Rate Fallowing Posterior Total Hip Arthroplasty with Intra-Osseous Soft Tissue Repair. MOJ Orthop Rheumatol 8, 324.
17. Murray, T.G., Wetters, N.G., Moric, M., Sporer, S.M., Paprosky, W.G., & Della Valle, C.J. (2012). The use of abduction bracing for the prevention of early postoperative dislocation after revision total hip arthroplasty. The Journal of arthroplasty, 27(8), 126-129.
18. Taheriazam, A. & Saeidinia, A (2017). Conversion of failed hemiarthroplasty to total hip arthroplasty: a short-term follow-up study. Medicine (Baltimore).
19. Moura, D.L. & Figueiredo, A (2018). High congenital hip dislocation in adults–arthroplasty and functional results. Rev. Bras. Ortop. (English Ed. 53, 226–235.
20. Purvance, I., Dusak, W.S., Stanu, G.N.P. & Astawa, N.M. P.D (2020). Functional outcome after total hip replacement following 30 years neglected posterior hip dislocation: a rare case report. International Journal of Research in Medical Sciences. 2020 Mar; 8(3):
1152-1155.
