Management and Outcomes of Hip Fractures in Lower Limb Amputees: A Case Series

Abstract

Background

Hip fractures in amputees pose a significant challenge for the orthopedic surgeon due to technical difficulties and there is no standardisation in their management. Their treatment is consequently left to the surgeon’s ingenuity. The aim of this study is to describe the clinical characteristics and outcome of a series of hip fractures in lower limb amputees.

Methods

A total of 12 patients and 15 hip fractures in lower limb amputees were included. Amputations below the malleoli and prosthetic surgery due to osteoarthritis constitute the exclusion criteria. Demographic, amputation-related and fracture data as well as radiological, functional, and clinical outcomes were collected through the patients' medical records.

Results

Age at fracture and at amputation were different depending on the cause of amputation. Most patients (10/12) were male. Seven patients had an infracondylar amputation and five patients had a supracondylar amputation. Ten hip fractures were on the same side of the amputation, three were contralateral and one was bilateral. Pertrochanteric (6/15) and subcapital (5/15) were the main types observed. Different traction methods and surgical procedures were used. We observed no significant differences in terms of outcome regardless of the fracture, traction method, and surgical management. No complications related to surgery or during follow-up were found. Mortality at one year postoperatively was absent.

Conclusion

Provided an experienced orthopaedic surgeon, a pre-operative assessment, a comprehensive surgical planning, and a multidisciplinary rehabilitation strategy are present; a satisfactory outcome is to be expected.

Introduction

Hip fractures represent a clinical challenge since they are considered one of the key causes of morbidity and mortality [1]. Furthermore, their incidence is expected to increase in the upcoming years due to the progressive ageing of the worldwide population amongst other relevant factors [2].

Amputations occur because of traumatic injuries and systemic conditions such peripheral arterial disease. This medical condition is strongly associated with diabetes. As there is a higher prevalence of diabetes in the elderly, the number of amputees is considered to potentially increase with age [3–5]. In addition, lower limb amputees are at increased risk to develop osteoporosis and fragility hip fractures as they suffer from accelerated bone density loss regardless of their age [6, 7].

Hip fractures amongst lower limb amputees are rare [8]. However, they present a daunting task related to surgical preparation, approach, and technique owing to difficulties in the patient positioning, fracture reduction/manipulation and stump fixation on the fracture table. There are few articles published on this topic. Consequently, the operative management needs to be reviewed to develop treatment plans to permit these patients to return to their previous mobility and activity status [9–11].

The main objective of this study is to describe the clinical characteristics and outcome of a series of lower limb amputees with hip fractures, in the search of a standard of care for this rare, but complex presentation.

Methods

The objective and protocol of this study conformed to the principles described in the Declaration of Helsinki. This research has been approved by the IRB of the authors. All patients provided informed consent prior to participation in this study. This study is a single-center case series from 1-1-2015 to 31-12-2021.

A total of 15 hip fractures in 12 amputee patients, who had previously sustained supramalleolar amputations of the lower limb, were included. Patients with amputations below the malleoli were excluded, as well as patients who underwent prosthetic surgery due to osteoarthritis and therefore did not have a hip fracture.

The following data were recorded: demographic data (age, gender, follow-up time, associated comorbidities); amputation-related data (below or above the knee, the same or different side of hip fracture, cause, time since amputation, and whether prosthesis-wearing); hip fracture data (location, type of fracture, and mechanism); surgical data (traction, type of surgery, and complications); finally, radiological, functional, and clinical outcomes. Data were collected through the patients' medical records.

Results

Table 1 shows the baseline data of the 12 patients. There were 15 hip fractures as two patients had two fractures at different times and one patient had two fractures at the same time after a fall from height. Age at hip fracture and age at amputation were different depending on the cause of amputation, being vascular cause more common in older patients compared to traumatic cause in younger patients. Most patients were male (ten cases). Seven patients had an infracondylar amputation and five patients had a supracondylar amputation. Ten femur fractures were on the same side of the amputation, three were contralateral and one was bilateral.

Table 1.

Baseline characteristics of 12 included patients

Patient	Age hip fracture	Age limb amputation	Gender	Amputation location	Side	Etiology
1	71	9	F	Infracondylar	Bilateral	Traumatic
2	52	–	M	Supracondylar	Same side	Vascular diabetes
	66	–	M	Bilateral supracondylar	Same side	Vascular diabetes
3	45	25	M	Supracondylar	Same side	Vascular diabetes
4	85	82	M	Infracondylar	Different side	Traumatic
5	75	74	M	Infracondylar	Same side	Vascular diabetes
6	65	63	M	Infracondylar	Same side	Vascular diabetes
7	91	77	F	Infracondylar	Same side	Osteomyelitis
	90	77	F	Infracondylar	Different side	Osteomyelitis
8	74	71	M	Bilateral supracondylar	Same side	Vascular diabetes
9	68	68	M	Supracondylar	Same side	Vascular
10	82	74	M	Supracondylar	Different side	Vascular
11	46	41	M	Infracondylar	Same side	Chondrosarcoma
12	56	30	M	Infracondylar	Same side	Traumatic

Table 2 shows the main characteristics of the hip fracture, the surgery and the functional outcomes. Nine patients had a casual fall, four fell from the wheelchair, and one patient presented a sequela of a pertrochanteric fracture. Six fractures were pertrochanteric, five were subcapital, three were subtrochanteric, and one was supracondylar. Table 2 shows the different traction methods and surgical procedures used in each case. No complications related to surgery or during follow-up were found. Mortality at one year postoperatively was absent. Two patients died (one 2 years after hip fracture and one 3 years after). Only one patient required a transmetatarsal amputation after a hip fracture in the contralateral extremity.

Table 2.

Principal features of hip fracture, surgery and functional outcomes

Patient	Walk before fracture	Fracture location	AO classification	Mechanism	Traction	Treatment	Outcomes
1	No assistance and prosthesis	Pertrochanteric and subcapital	31a12 and 31b1	Fall from height	Elastic bandage	DHS pertrochanteric and canulated screws subcapital	No assistance and prosthesis
2	Wheelchair	Pertrochanteric	31a1	Fall from height	–	Non-operative	Wheelchair
	Wheelchair	Subtrochanteric	32a3	Fall from wheelchair	No traction	Short gamma nail 170 × 10 125°	Wheelchair
3	Wheelchair	Subtrochanteric	33a2	Fall from wheelchair	No traction	Expert retrograde nail	Wheelchair
4	No assistance and prosthesis	Subcapital	31b3	Fall from height	–	Cemented Corail partial replacement	No assistance and prosthesis
5	Crutches	Subcapital	31b4	Fall from height	–	Cemented Euromed bipolar partial replacement	Walker and prosthesis
6	No assistance	Subcapìtal	31b3	Fall from height	–	Cemented Euromed bipolar partial replacement	Crutches
7	Walker	Subcapital	31b3	Fall from height	–	Cemented Corail partial replacement	–
	–	Subtrochanteric	32c3	Fall from height	Boot	2 cerclages + long gamma nail 11 × 340 125° + 2 distal locking screws	–
8	Wheelchair	Pertrochanteric	32a3	Fall from wheelchair	Orthopedic	Non-operative	Wheelchair
9	Crutches	Pertrochanteric sequel	32b2	Pertrochanteric sequel	No traction	emo gamma2	Crutches home and wheelchair outdoors
10	Walker home and wheelchair outdoors	Pertrochanteric + peri-implant	32a2	Fall from height	No traction	2 cerclages + emo gamma + 2 distal locking screws	Walker home and wheelchair outdoors
11	No assistance and prosthesis	Pertrochanteric	31a2	Fall from height	Transtibial steinman pin	PFNA 200 × 11 130°	No assistance and prosthesis
12	Cane	Supracondylar	33a3	Fall from height	Elastic bandage	Liss plate	Cane

Discussion

Hip fractures pose a major challenge to orthopedic surgeons because of the patients’ characteristics and its frequent presentation: 45,000 hip fractures were treated in 2010 in Spain [12]. In addition, 2.6 million and 6.25 million hip fractures are expected globally by 2025 and 2050, respectively [13, 14]. Cardiovascular disease risk factors (i.e., diabetes, hypertension, dyslipidemia) are associated with the development of peripheral arterial disease and consequently with a higher incidence of amputations. Amongst the young population, amputees are mainly due to trauma such as road traffic accidents and military operations. Major lower limb amputees’ prevalence generally ranges from 3.6 to 6.84 per 10,000 people [14–16].

Even though hip fractures in major lower limb amputees are uncommon, they present a daunting task to the orthopedic surgeon at the positioning, fracture reduction and choice of the fixation method. Non-amputees are regularly positioned on a fracture table with the fracture side foot strapped in a boot piece which allows limb traction and rotation. This attachment therefore eases fracture manipulation and reduction. In these patients, their contralateral limb is strongly fixed to the thigh support groove on the fracture table with their hip joint bent and abducted to facilitate the fluoroscopy image intensifier placement [17].

On the contrary, this positioning cannot be accomplished in major lower limb amputees which complicates the manipulation and reduction of the hip fracture. In addition, the higher the level of the amputation, the more difficult this task becomes as the available stump for traction and rotation is shorter [17].

After a careful review of the literature, few studies have been published related to this topic. Moreover, they are predominantly case reports and solely one retrospective comparative study to be found [8–10, 17–22].

Baseline characteristics of this case series consist of a mean age of 69.00 ± 15.20 and 16.66% of female patients. In 2021, Haleem et al. [23] compared 28 hip fractures in amputees in the period 1996–2017 with a database of 7787 hip fractures. They described a mean age in years of 78.00 ± 9.90 and 57.1% of their amputees were female patients. Both studies present mean ages above 65 years which is congruent with the above-mentioned high rates of amputees in the elderly [4, 5]. There is however a difference in the distribution of female patients: 16.66% in our series vs 57.10% in theirs. This fact might be explained because of Haleem et al.’s [23] longer follow-up period or due to different amputation causes. As they do not present the amputation etiology this hypothesis cannot be confirmed.

As described in the literature, vasculopathy and traumatic injury were the main cause of amputation in this cohort with 7 and 3 patients, respectively. In five of those seven amputees due to vasculopathy the trigger of the underlying condition was diabetes [4, 5].

Regarding laterality, most hip fractures (10/15) occurred on the amputation side. Accelerated loss of bone density in the amputated limb might be the justification as described by Flint et al. [7].

The mechanism of 13 of all sustained fractures was low energy trauma: either fall from own height or fall from the wheelchair. There is evidence suggesting that 50% of amputees report falls at least once a year with rates up to 20% requiring medical care and over 40% of these resulting in some sort of injury [24]. Our findings are hence consistent with previous reports such as Gonzalez et al.’s which described falls usually happened whilst transferring [25] as well as with Haleem et al.’s since they showed that over 90% of these low-energy falls occurred in known familiar surroundings [23].

In our series, subcapital and pertrochanteric fractures were the predominant types observed with 5 and 4 cases respectively. The purpose of surgery in subcapital fractures is to restore neck-shaft angle/offset and normal hip abduction function. Most of these fractures were managed with a standard anterolateral approach for a bipolar cemented partial hip replacement as presented in Table 2.

On the contrary, pertrochanteric fractures in non-amputees are regularly managed surgically with short intramedullary nails with proximal lag screw fixation. This operation is performed on a traction table under an image intensifier. As presented in Table 2, there is substantial heterogeneity in the management of pertrochanteric fractures: two conservatively, one with PFNA nail and one with DHS and cannulated screws (this case involved a pertrochanteric and subcapital fracture simultaneously). Conservative management is rare in non-amputees due to poor functional outcomes. Nevertheless, both patients treated conservatively resulted in a functional outcome which enabled wheelchair mobility. We only have data regarding one of them with no significant changes in functional status (pre- and post-fracture with wheelchair mobility).

Surgical management of hip fractures in amputees is challenging since proper traction is impaired as the stump cannot be fixated with regular devices. As fractures in these patients are rather rare there is no standardisation in stump fixation. The authors have put into practice several techniques in this process: individually modified fracture tables, boot piece rotation alteration, usage of additional skin traction bands and skeletal traction [6, 17, 26].

Consequently, it lies on the surgeon’s experience and ingenuity to devise a plan for stump fixation. In our series we applied a wide-ranging variety of methods since two patients had their stump fixed with an elastic bandage, one with a transtibial Steinmann pin, one with a boot and four utilized no traction. As observed in Table 2, there is no significant difference between the stump fixation method applied and the outcomes. Unfortunately, there are no data regarding fixation-derived setbacks encountered by the surgeon which, yet appropriately solved, cannot hint which fixation technique may be most advantageous.

In terms of outcome, we observed no significant differences regardless of the fracture, applied traction method and surgical management. We could gather data from 11 hip fractures regarding the outcome. There was either no change or slight improvement (patient 5 in Table 2) in functional status in nine patients. On the contrary, 2 patients suffer a decrease in their functional status (patients 6 and 9 in Table 2). In sum, these findings suggest that most hip fractures in amputees are treated successfully despite their complexity and rare presentation.

In conclusion, this case series is to our knowledge one of the largest reported in the literature on hip fractures in amputees. These fractures pose a major technical challenge to the orthopaedic surgeon. In addition, there are currently no guidelines available for the treatment of this injury. However, with an experienced orthopaedic surgeon, an in-depth patient-specific pre-operative evaluation, comprehensive surgical planning and multidisciplinary rehabilitation strategy hip fractures in amputees can be successfully treated with good outcomes.

The main limitation of this study was the lack of subgroups according to the fracture type and laterality. However, this limitation might be overcome since it is one of the largest case series of hip fractures in lower limb amputees up to date. Other limitations to be mentioned are the absence of a functional score and those derived from the study design of a case series.

Declarations

Conflict of interest

On behalf of all authors, the corresponding author states that there is no conflict of interest.

Ethical standard statement

This article does not contain any studies with human or animal subjects performed by any of the authors.

Informed consent

For this type of study informed consent is not required.