Orthopedics

Operative Versus Nonoperative Management of Pipkin Type-II Fractures Associated With Posterior Hip Dislocation

Zhi-wen Chen, MD; Wen-liang Zhai, MD; Zhen-qi Ding, MD; Ke-jian Lian, MD; Liang-qi Kang, MD; Lin-xin Guo, MD; Hui Liu, MD; Bin Lin, MD

Abstract

Little has been written on randomized, controlled studies of operative versus nonoperative management of Pipkin type-II fractures associated with posterior dislocation of the hip. It is difficult to validate the optimal management of these fractures. The goals of this study were to (1) evaluate the results of conservative and surgical treatment for Pipkin type-II fractures associated with posterior dislocation of the hip and supply the optimal management for these fractures and (2) identify whether the Smith-Petersen approach is a safe and reliable surgical approach for Pipkin type-II fractures.

Twenty-four patients were randomly divided into 2 groups: the conservative group (n=12) was treated by closed reduction, and the surgical group (n512) was treated by primary open reduction internal fixation (ORIF) by bioabsorbable screws via a Smith-Petersen approach. Minimum follow-up was 24 months. Functional outcome was measured using the Thompson and Epstein score and the d’Aubigné-Postel score. Heterotopic ossification was classified based on the Brooker classification. The outcome of the conservative group was worse than that of the surgical group (P=.037). Two patients in the conservative group needed joint replacement for avascular necrosis of the femoral head. Heterotopic ossification was found in 6 patients (1 patient in the conservative group and 5 in the surgical group).

Primary ORIF by bioabsorbable screws via a Smith-Petersen approach is an effective treatment for Pipkin type-II fractures associated with posterior dislocation.

The Pipkin classification system is the most commonly used to evaluate fractures (Figure 1). Pipkin type-II fracture of the femoral head associated with posterior dislocation of the hip is an uncommon but severe injury.1 Statistics show that 11.7% of hip dislocations were associated with a femoral head fracture and that 84% of patients had been victims of an automobile accident.2 The fracture itself, as well as posttraumatic changes such as heterotopic ossification, avascular necrosis of the femoral head, and osteoarthritis, may lead to a restriction in hip function and permanent disability, even in young patients.

The absence of a validated outcome instrument has contributed to the lack of absolute recommendations and indications for the most appropriate treatment of these injuries.3 Little has been written to date on prospective, randomized, controlled studies of operative versus nonoperative management of Pipkin type-II fractures, and no clear evidence exists that indicates whether to treat the fracture operatively or nonoperatively.

For Pipkin type-II fractures, the main surgical approaches include anterior (Smith-Peterson), posterior (Kocher-Langenbeck) and trochanteric-flip osteotomy approaches. Advantages and disadvantages of the different approaches have been the subject of previous studies, and controversies and inconsistencies exist concerning the optimal surgical approach for these fractures.3-12

The goals of this study were to (1) evaluate the results of conservative and surgical treatment for Pipkin type-II fractures associated with posterior dislocation of the hip by a randomized, controlled trial and supply the optimal management for these fractures, and (2) identify whether the Smith-Petersen approach is a safe and reliable surgical approach for Pipkin type-II fractures.

We designed a randomized, controlled trial to compare the results of conservative and surgical treatment for Pipkin type-II fractures associated with posterior dislocation of the hip. Inclusion criteria were patients aged 18 to 60 years with close Pipkin type-II fractures of the femoral head associated with posterior hip dislocation, time elapsed between injury and successful closed reduction or ORIF <12 hours, and time to follow-up visit >2 years. Exclusion criteria were associated posterior wall acetabular fracture, previous hip injury, associated nerve or vascular injury, pathological fracture of the femoral head, and associated severe multiple injuries, including brain injury.

All patients were included based on written informed consent. This study was approved by the Institutional Review Board and Ethics…

Abstract

Little has been written on randomized, controlled studies of operative versus nonoperative management of Pipkin type-II fractures associated with posterior dislocation of the hip. It is difficult to validate the optimal management of these fractures. The goals of this study were to (1) evaluate the results of conservative and surgical treatment for Pipkin type-II fractures associated with posterior dislocation of the hip and supply the optimal management for these fractures and (2) identify whether the Smith-Petersen approach is a safe and reliable surgical approach for Pipkin type-II fractures.

Twenty-four patients were randomly divided into 2 groups: the conservative group (n=12) was treated by closed reduction, and the surgical group (n512) was treated by primary open reduction internal fixation (ORIF) by bioabsorbable screws via a Smith-Petersen approach. Minimum follow-up was 24 months. Functional outcome was measured using the Thompson and Epstein score and the d’Aubigné-Postel score. Heterotopic ossification was classified based on the Brooker classification. The outcome of the conservative group was worse than that of the surgical group (P=.037). Two patients in the conservative group needed joint replacement for avascular necrosis of the femoral head. Heterotopic ossification was found in 6 patients (1 patient in the conservative group and 5 in the surgical group).

Primary ORIF by bioabsorbable screws via a Smith-Petersen approach is an effective treatment for Pipkin type-II fractures associated with posterior dislocation.

The Pipkin classification system is the most commonly used to evaluate fractures (Figure 1). Pipkin type-II fracture of the femoral head associated with posterior dislocation of the hip is an uncommon but severe injury.1 Statistics show that 11.7% of hip dislocations were associated with a femoral head fracture and that 84% of patients had been victims of an automobile accident.2 The fracture itself, as well as posttraumatic changes such as heterotopic ossification, avascular necrosis of the femoral head, and osteoarthritis, may lead to a restriction in hip function and permanent disability, even in young patients.

Figure: Pipkin classifi cation of femoral head fractures with posterior hip dislocations.
Figure: Pipkin classification of femoral head fractures with posterior hip dislocations.

The absence of a validated outcome instrument has contributed to the lack of absolute recommendations and indications for the most appropriate treatment of these injuries.3 Little has been written to date on prospective, randomized, controlled studies of operative versus nonoperative management of Pipkin type-II fractures, and no clear evidence exists that indicates whether to treat the fracture operatively or nonoperatively.

For Pipkin type-II fractures, the main surgical approaches include anterior (Smith-Peterson), posterior (Kocher-Langenbeck) and trochanteric-flip osteotomy approaches. Advantages and disadvantages of the different approaches have been the subject of previous studies, and controversies and inconsistencies exist concerning the optimal surgical approach for these fractures.3-12

The goals of this study were to (1) evaluate the results of conservative and surgical treatment for Pipkin type-II fractures associated with posterior dislocation of the hip by a randomized, controlled trial and supply the optimal management for these fractures, and (2) identify whether the Smith-Petersen approach is a safe and reliable surgical approach for Pipkin type-II fractures.

Materials and Methods

We designed a randomized, controlled trial to compare the results of conservative and surgical treatment for Pipkin type-II fractures associated with posterior dislocation of the hip. Inclusion criteria were patients aged 18 to 60 years with close Pipkin type-II fractures of the femoral head associated with posterior hip dislocation, time elapsed between injury and successful closed reduction or ORIF <12 hours, and time to follow-up visit >2 years. Exclusion criteria were associated posterior wall acetabular fracture, previous hip injury, associated nerve or vascular injury, pathological fracture of the femoral head, and associated severe multiple injuries, including brain injury.

All patients were included based on written informed consent. This study was approved by the Institutional Review Board and Ethics Committee of our institution.

In the conservative group, immediate closed reduction of a fracture dislocation of the hip was performed under general or epidural anesthesia. The limb was put into skeletal traction for 6 weeks after successful closed reduction to restrict hip movement. Radiographs were taken immediately after successful closed reduction, at 12 weeks postoperatively, and every 6 months thereafter. Functional exercises of isometric contraction of the quadriceps were started the day after closed reduction. When the radiographs at 12 weeks showed fracture healing, progressive weight bearing and active exercises were started. Full weight bearing was allowed 6 months after successful closed reduction, but patients were instructed to avoid high-impact training.

In the surgical group, closed reduction was not attempted. After admission, ORIF was performed immediately via the Smith-Petersen approach under general or epidural anesthesia. With patients in the supine position, an incision was started at the middle of the iliac crest and continued anteriorly to the anterosuperior iliac spine and then distally and slightly laterally 10 to 12 cm, dividing the superficial and deep fasciae and freeing the attachments of the gluteus medius and the tensor fasciae latae muscles from the iliac crest. With a periosteal elevator, the periosteum, with the attachments of the gluteus medius and minimus muscles, was stripped from the lateral surface of the ilium, and bleeding from the nutrient vessels was controlled by packing the interval between the ilium and the reflected muscles. Dissection was carried through the deep fascia of the thigh and between the tensor fasciae latae laterally and the sartorius and rectus femoris medially. The ascending branch of the lateral femoral circumflex artery (5 cm distal to the hip joint) was clamped and ligated.

The lateral femoral cutaneous nerve was passed over the sartorius 2.5 cm distal to the anterosuperior spine and retracted to the medial side. If the structures at the anterosuperior spine were contracted, the spine was freed with an osteotome and allowed to retract with its attached muscles to a more distal level. The capsule was exposed and incised transversely and revealed the femoral head and the proximal margin of the acetabulum. The capsule may also be sectioned along its attachment to the acetabular labram (cotyloid ligament) to give the required exposure. If necessary, the ligamentum teres may be divided with a curved knife or with scissors and the femoral head dislocated, giving access to all parts of the joint. The femoral head was dislocated to anterior of the hip, and the head fragment was reduced and fixed with 2 to 3 bioabsorbable polylactate screws (2.5-3.0 mm). The intra-articular soft tissue and small intra-articular bone fragments were cleaned up before hip reduction. The limb was put in skin traction for 6 weeks postoperatively to restrict hip movement. Other postoperative management was the same as that for the conservative group. All surgical procedures were performed by the same surgeon (B.L.).

All patients were followed up by an independent person for at least 2 years. Patients were evaluated by radiographic outcomes, including rates of avascular necrosis of the femoral head and heterotopic ossification, and clinical outcomes using the Thompson and Epstein score13 and the d’Aubigné-Postel score.14 Heterotopic ossification was determined by the Brooker classification.15

Data were expressed as mean±standard deviation. Statistical evaluation included separate unpaired t test, Pearson chi-square test, and Wilcoxon rank-sum test. The Wilcoxon rank-sum test was used as a nonparametric test to compare distributions in the 2 treatment groups. The tests were performed using SPSS 12.0.1 for Windows (SPSS Inc, Chicago, Illinois). A P value <.05 was considered statistically significant.

Results

From 2000 to 2008, 24 patients with Pipkin type-II fractures of the femoral head were treated and divided randomly into 2 groups according to sequence of admission. Each group comprised 12 patients. Patient data are summarized in Tables 1 and 2.

Table 1: Conservative Group Demographics

Table 2: Surgical Group Demographics

In the conservative group, 9 men and 3 women had an average age at the time of injury of 39.8±10.20 years (range, 26-59 years). Nine patients sustained their injuries during a traffic accident, 2 fell from a height, and 1 was hit by a falling wall. The time elapsed from injury to successful closed reduction was 5.2±2.40 hours (range, 1.5-10.0 hours). In the surgical group, 8 men and 4 women had an average age at the time of injury of 37.5±12.14 years (range, 19-52 years). Ten patients sustained their injuries during a traffic accident, and 2 fell from a height. The time elapsed from injury to successful ORIF was 7.0±2.07 hours (range, 4.5-11.5 hours). Minimum follow-up was 26 months (mean, 39.1±8.79 months; range, 26-60 months) in the conservative group and 24 months (mean, 36.9±11.65 months; range, 24-65 months) in the surgical group. The 2 groups were comparable (P>.05) with respect to age, sex, duration from injury to reduction, and follow-up time (Table 3).

Table 3: Comparison of Baseline Data in Both Groups

The femoral head fractures did not achieve anatomical reduction in the conservative group (Figures 2-5), but achieved anatomical reduction in the surgical group (Figures 6, 7). Outcomes by Thompson and Epstein score and d’Aubigné-Postel score were classified equally. The treatment results were divided into 4 grades: in the conservative group, the result was excellent in 2 patients, good in 3, fair in 5, and poor in 2. In the surgical group, the outcome was excellent in 5 patients, good in 5, fair in 2, and poor in none. Wilcoxon rank-sum test analysis of these data reached statistical significance (P=.037). The outcome was significantly better in the surgical group than the conservative group (Table 4).

Figure 2: Radiograph of Pipkin type-II fracture Figure 3: CT scan of Pipkin type-II fracture Figure 4: Radiograph of Pipkin type-II fracture
Figure 2: Radiograph of Pipkin type-II fracture associated with posterior dislocation of the hip. Figure 3: CT scan of Pipkin type-II fracture associated with posterior dislocation of the hip. Figure 4: Radiograph of Pipkin type-II fracture after closed reduction.

Figure 5: CT scan of Pipkin type-II fracture Figure 6: Radiograph of Pipkin type-II fracture after ORIF Figure 7: CT scan of Pipkin type-II fracture after ORIF
Figure 5: CT scan of Pipkin type-II fracture after closed reduction. Figure 6: Radiograph of Pipkin type-II fracture after ORIF. Figure 7: CT scan of Pipkin type-II fracture after ORIF.

Table 4: Outcomes and Complications at Last Follow-up

Avascular necrosis of the femoral head was not found in the surgical group. In the conservative group, 2 patients required joint replacement for avascular necrosis of the femoral head. Heterotopic ossification was found in 6 patients, 1 in the conservative group and 5 in the surgical group. Chi-square analysis failed to reach statistical significance in the complication of avascular necrosis (P=.140). The complication of heterotopic ossification reached a near statistically significant difference (P=.059) (Table 4).

Discussion

Fractures of the femoral head have been well described in the literature, but meaningful conclusions have proven difficult because of the lack of high-quality randomized, controlled studies.2 Little has been written to date on prospective, randomized, controlled studies of operative versus nonoperative management of Pipkin type-II fractures, and there is no clear evidence indicating whether to treat these fractures operatively or nonoperatively. We therefore reported the radiographic outcomes, including rates of avascular necrosis of the femoral head and heterotopic ossification, and clinical outcomes using the Thompson and Epstein score and the d’Aubigné-Postel score of 24 patients with Pipkin type-II fractures managed conservatively or surgically with the Smith-Peterson approach during an 8-year period.

Our study has numerous limitations. First, the number of patients enrolled in the trial was relatively small. A power analysis indicated that a group of 10 patients would be sufficient to determine whether there was a better outcome. We did not anticipate important differences in rates of avascular necrosis of the femoral head and heterotopic ossification between the groups, and although we found none, the group size would not be sufficient to detect small differences in rates of avascular necrosis of the femoral head and heterotopic ossification. Second, the assessor was also the caregiver and the person who informed the patients about the goals of the study. Although the intervention types did not allow blinding of patients, the study would have been stronger by blinding the assessor for the functional outcome measurement (clinical and radiographic hip score) or by using an independent assessor. Third, this study had a comparative effectiveness design, and the lack of a true control group may mean that the changes observed in both groups were not real. Fourth, the follow-up visit was limited, with an average follow-up of 39.1±8.79 months in the conservative group and 36.9±11.65 months in the surgical group. The study data should be viewed as preliminary and requiring further development to substantiate conclusions regarding rate of avascular necrosis of the femoral head.

The recommended treatment methods have varied from primary closed reduction or ORIF for Pipkin type-II fractures of the femoral head associated with posterior dislocation of the hip. Epstein et al5 suggested that all traumatic dislocations of the hip must be treated as surgical emergencies, that multiple attempts at closed reduction are contraindicated, and that the good results after primary open reduction were better than closed or closed followed by open reduction. Some studies suggest that conservative methods should be considered initially, although treatment of this injury is difficult.16,17 Others support immediate primary open reduction of both dislocation and fractured fragments, because further trauma to the injured soft tissues can be avoided and loose, harmful fragments can be simultaneously debrided from the joint space.4,5,18,19 Prerequisites of such treatment are anatomic reduction of hip dislocation and femoral head fracture, but these are all difficult by closed reduction. A study by Henle et al8 showed that only 1 in 12 patients showed an anatomic fracture position after closed reduction; if the fracture gap within the joint showed a displacement of >2 mm, operative treatment was indicated to improve reduction.

Nonoperative management cannot clean up the intra-articular soft tissue and small bone fragments. We feel that the intra-articular soft tissue, small intra-articular bone fragments, and malunion lead to osteoarthritis of the hip and avascular necrosis of the femoral head. Our study shows that primary ORIF for Pipkin type-II fractures associated with posterior hip dislocation had a better outcome than primary closed reduction. Although the complication of avascular necrosis of the femoral head failed to reach statistical significance in our study, taking into account the small number of patients, we presumed the complication was high in conservative management. These results show that primary ORIF is an acceptable treatment of Pipkin type-II fractures of the femoral head.

The matter of which operative approach should be used for the surgical treatment of femoral head fractures remains controversial. Some studies advocate the use of Kocher-Langenbeck approach and advise against the Smith-Peterson approach, supposing that the latter would damage any residual blood supply to the femoral head.4,5 Another study shows that when evaluated with an odds ratio analysis, the use of Kocher-Langenbeck posterior approach was associated with a 3.2-times-higher incidence of avascular necrosis development when compared with the Smith-Petersen approach.3 Gautier et al20 showed that the medial femoral circumflex artery, mainly its deep branch, supplies the blood to the femoral head. Recently, a trochanteric-flip osteotomy approach has been recommended for femoral head fractures.7,8,21 However, this approach increases the risk of nonunion of the greater trochanter. In the current study and other studies,3,10,12 the recommendation for treatment of Pipkin type-II fractures is the Smith-Petersen approach. There is a significant decrease in operative time and estimated blood loss, and the approach improves visualization and fixation with the anterior approach. The drawback in patients treated with an anterior approach was the development of more functionally significant heterotopic ossification, although the overall functional outcome was identical in both groups.12 In our study, the outcome of the surgical group was better than the conservative group, but the incidence of heterotopic ossification in the surgical group was high. Prophylaxis with indomethacin or low-dose radiation should be considered to minimize heterotopic ossification.

It was difficult to ensure a safe time interval between injury and reduction of traumatic dislocation of the hip joint. McMurtry and Quaile22 showed that the joint should be relocated within 6 hours; failure to do so increases the risk of avascular necrosis of the femoral head with resultant early degenerative joint disease, often in an otherwise fit, young patient. Epstein et al5 indicated that reduction within 24 hours gives better results than late reduction. Our study shows that reduction by surgical treatment for these fractures within 12 hours can give good results. 

References

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Authors

Drs Chen, Zhai, Ding, Lian, Kang, Guo, Liu, and Lin are from the Department of Orthopedics, the 175th Hospital of PLA, Traumatic Orthopedics Center of PLA, Southeast Hospital of Xiamen University, Zhangzhou Fujian Province, PR China.

Drs Chen, Zhai, Ding, Lian, Kang, Guo, Liu, and Lin have no relevant financial relationships to disclose.

Correspondence should be addressed to: Bin Lin, MD, the 175th Hospital of PLA, Southeast Hospital of Xiamen University, Zhanghua Rd, Zhangzhou Fujian Province, PR China, 363000 (lbin175@tom.com).

doi: 10.3928/01477447-20110317-09

10.3928/01477447-20110317-09

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