|Year : 2022 | Volume
| Issue : 1 | Page : 24-26
Management of hip dislocation following DHS fixation: A rare case report
Nabarun Saha1, Amarendra Nath Roy1, Anant Kumar Garg1, Sunit Hazra2, Sanjay Kumar2
1 Murshidabad Medical College, Berhampore, Kolkata, India
2 R G Kar Medical College, Kolkata, West Bengal, India
|Date of Submission||10-Jun-2022|
|Date of Acceptance||20-Jun-2022|
|Date of Web Publication||30-Jun-2022|
Murshidabad Medical College, Berhampore, Kolkata, West Bengal
Source of Support: None, Conflict of Interest: None
Dynamic hip screw (DHS) is an excellent implant for fixation of intertrochanteric fracture which helps the fracture components to slide together and impact, thus converting shearing force to compressive force. However, increased bending load over medial femoral cortex, excessive collapse at the fracture site, and unwanted rotation of proximal fragment lead to some cases of failure. Dislocation of hip following DHS fixation is the rarest of rare complications and probably not reported in literatures. We present one such case managed by two-staged total hip replacement using stability-range of motion prosthesis.
Keywords: Dislocation of hip, dynamic hip screw, intertrochanteric fracture, SROM, total hip replacement
|How to cite this article:|
Saha N, Roy AN, Garg AK, Hazra S, Kumar S. Management of hip dislocation following DHS fixation: A rare case report. Int J Orthop Surg 2022;30:24-6
|How to cite this URL:|
Saha N, Roy AN, Garg AK, Hazra S, Kumar S. Management of hip dislocation following DHS fixation: A rare case report. Int J Orthop Surg [serial online] 2022 [cited 2022 Aug 11];30:24-6. Available from: https://www.ijos.in/text.asp?2022/30/1/24/348193
| Introduction|| |
The incidence of proximal femoral fractures is rising because of two reasons: (1) high life expectancy superadded with osteoporosis and (2) increasing number of high velocity road traffic accidents., It is one of the common causes of morbidity and mortality in elderly patients. Much earlier, Whitman in 1902 advocated that reduction of these fractures by traction, abduction, internal rotation, and stabilization in hip spica cast lessens the frequency of life-threatening complications. Later, a variety of implants evolved aid in stabilization of fracture by internal fixation. The choice of implant depends on fracture pattern (intracapsular or extracapsular, stable or unstable). Out of various fixation devices, dynamic hip screw (DHS) is the most widely used. DHS is an excellent implant which helps the fracture components to slide together and impact, thus converting shearing force to compressive force. However, increased bending load over medial femoral cortex, excessive collapse at the fracture site, and unwanted rotation of proximal fragment lead to some cases of failure.,
| Case Report|| |
A 65-year-old male presented to our hospital OPD with chief complaints of difficulty in mobilization and gradual onset pain in the left hip since last 9 months. He suffered intertrochanteric fracture due to domestic fall 1 year back and was treated elsewhere. Immediate post-operative X-ray showed stable fixation with 135° DHS implant and SS wire [Figure 1]B. The patient was able to walk with support for a month. But gradually there was insidious onset pain in the left hip along with limp which progressed and ultimately made the patient bedridden for 4 months. Subsequent X-rays supported gradual sublaxation of the left hip with DHS implant in situ, wandering acetabulum, high riding left hip, pseudo-acetabulum formation, excessive collapse at the fracture site, and medialization of shaft with displaced greater trochanter [Figure 1]C. On examination, in the left side, there was shortening of 4 cm, fixed flexion deformity of 20°, and adduction deformity of 15°. There were no signs of infection. Movements were limited and painful in all directions. Routine blood examination reports show total white blood cell count—9300, erythrocyte sedimentation rate—28 and C-reactive protein—non reactive. Staged surgery was planned. At first, all implants were removed followed by thorough wound debridement [Figure 1]D. Tissue culture turned to be negative. Adductor tenotomy done and the patient put on upper tibial skeletal traction for 3 weeks. A digital X-ray of both hip AP and left hip lateral view at this stage depicted three main problems which need to be fixed: (1) false acetabulum which needs bone grafting, (2) distorted proximal femoral anatomy, and (3) trochanteric non-union. Both problems 2 and 3 can be solved by either Sivash-Range of Motion (SROM) or long stem total hip replacement (THR). We planned for SROM THR.
|Figure 1: Initial X-ray at the time of trauma (A), immediate post-operative radiograph, operated elsewhere by DHS fixation (B), dislocated left hip in post-operative DHS fixation (C), and AP and lateral radiograph after implant removal (D)|
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| Surgical Technique|| |
Under epidural anaesthesia through standard posterior approach, greater trochanter was osteotomized preserving abductor mechanism [Figure 2]A. Femoral head extracted and false acetabulum identified [Figure 2]B. Femoral head was prepared for bone grafting the false acetabulum [Figure 2]C and fixed with multiple canulated cancellous screws [Figure 2]D. Next, acetabulum was prepared and uncemented cup implanted [Figure 3]A. Femoral canal was prepared and hydroxyapatite-coated porous sleeve inserted followed by stem by checking anteversion [Figure 3]B. Abductor mechanism reconstructed with SS wire [Figure 3]C. Hemostasis secured and wound closed in layers.
|Figure 2: Through standard posterior approach osteotomy of greater trochanter (A), identification of false acetabulum (B), preparing femoral head for bone grafting (C), and bone grafting false acetabulum and fixation with screws (D)|
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|Figure 3: Acetabular cup preparation (A), hydroxyapatite porous sleeve insertion (B), C-arm image showing Sivash-Range of Motion (SROM) THR with abductor mechanism reconstruction (C), and post-operative AP and lateral radiograph (D) |
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Intravenous antibiotics continued for 3 days. Drain removed after 48 h. Physiotherapy started from post-operative Day 1 and weight-bearing allowed with a four-step walker after 2 weeks.
| Discussion|| |
Hip dislocation following DHS fixation is very rare. Only three cases have been reported so far. Extensive search in literature is carried out to know possible causes of such dislocations.
Munjal and Krikler reported a case of atraumatic hip dislocation 2 weeks following DHS fixation for intertrochanteric fracture. He performed open reduction and found complete stripping of anterior hip capsule, which was reattached. The author attributed initial soft tissue injury as a cause of dislocation rather than operative technique.
Melton et al. reported two cases of posterior dislocation of hip, following valgus fixation of an unstable intertrochanteric fracture. However, the authors proposed patient factors like parkinsonism and excessive alcohol intake along with malreduction as a cause of posterior dislocation.
Syed et al. reported a single case of anterior dislocation of hip following DHS fixation of intertrochanteric fracture. Possible causes of post-DHS hip dislocation are: (1) valgus reduction leading to decreased horizontal offset, (2) improper addressing of the abductor mechanism, (3) excessive capsular stripping during open reduction and bone grafting, and (4) reaming and tapping without anti-rotation screw, increases rotational malalignment.
Regarding hip reconstruction operation, bone grafting the false acetabulum is very much essential as it restores bone stock, provides good acetabular component stability, addresses limb length discrepancy. Both SROM THR and long stem THR could be used in this case. However, SROM THR outwits long stem THR with advantages such as (1) modular sleeve—which provides proximal stability independent of proximal femoral geometry and has various height and width options, (2) long fluted stem—which provides distal rotational stability and modularity of medial and vertical offsets due to different neck styles, and (3) porous coating proximal sleeve which has holes for greater trochanter fixation.
| Conclusion|| |
Hip dislocation following DHS operation, although rare, can occur if there is excessive valgus reduction, improper addressing of abductor mechanism, excessive capsular stripping during open reduction, and reaming and tapping without anti-rotation screw. Hence, such operative precautions should be taken. THR with SROM provides benefits of multilevel version modularity and proximal stability independent of proximal femoral geometry and holes for abductor mechanism reconstruction.
This research work is done at Murshidabad Medical College and Hospital, Berhampore, Kolkata, India. The author(s) of this article thank the administration of the Institute for kind support.
Financial support and sponsorship
Conflict of interest
All the authors declared that there is no conflict of interest.
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[Figure 1], [Figure 2], [Figure 3]