Neurovascular injury: avoiding catastrophe

The optimal screw-hole positions of the eccentric revision cup based on a morphological study

Background

Bridging bone defects in revision total hip arthroplasty is a challenge to orthopedic surgeons. The eccentric revision cup is a progression of jumbo cup. Our aim is to confirm the optimal screw-hole positions of the eccentric revision cup by morphological measurements of three-dimensional pelvic reconstruction.

Methods

Eighty CT images were converted to virtual three-dimensional bones. After simulating the surgery procedure, all available screw holes were inserted with the screws in virtual. By measuring the length of the screw in the pelvic bone, we determined the rich bone stock area. Then the screw holes were designed according to the characteristics of bone stock distribution. The peripheral screw-hole cluster and inner screw-hole cluster were studied respectively.

Results

For peripheral screw-hole cluster, five screw holes were evenly distributed between point A and point B in the thicker rim. For inner screw-hole cluster, screw hole 1 and screw hole 2 are the recommended inner screw holes.

Conclusion

The eccentric revision cup has inherited the strengths of jumbo cup besides several unique advantages, including using the peripheral screws enhancing primary stability; decreasing the shift of hip rotation center and restoring biomechanical function; reducing the risk of dislocation because of the smaller head-cup differences; increasing the contact area between the outer cup and the host bone while maintaining a normal inclination of the inner cup. In this study, we confirmed the optimal screw-hole positions of the eccentric revision cup by surgical simulation and morphological measurement. However, biomechanical tests are still being further explored.

A novel case of a pseudoaneurysm due to thermal injury from a cement hip spacer

Vascular injuries sustained during total hip replacements are associated with life- and limb-threatening complications. In the present report, we have described a novel vascular injury of an external iliac artery pseudoaneurysm repaired with an interposition vein graft. The vascular injury had been caused by heat from the curing process of a nearby cement hip spacer. During the curing process of bone cement, in vivo temperatures of ≤70°C can be reached, with such temperatures creating the potential for vascular injury. This case highlights the importance of limiting the exposure of surrounding neurovascular structures to bone cement to reduce the risk of thermal injury.

Relationship between use of screws and acetabular cup stability in total hip arthroplasty: a meta-analysis

Objective

The relationship between the use of screws and acetabular cup stability in total hip arthroplasty (THA) remains controversial. We evaluated cup stability in THA with and without the use of screws.

Methods

We performed a systematic literature search to identify studies on cup stability relative to the use of screws in patients undergoing THA before October 2018. Methodological quality assessment and data collection were performed by two individual reviewers. Meta-analysis was performed using Review Manager version 5.3.5.

Results

We included seven trials involving 1402 patients (1469 THAs): 767 patients (809 THAs) with screws and 635 patients (660 THAs) without screws. The findings of meta-analysis indicated that uncemented acetabular component fixation with the use of additional screws was not correlated with migration of the cup, migration on roentgen stereophotogrammetry, or reoperation after THA. Moreover, operation time was not significantly different according to whether screws were used. There was no relationship between use of additional screws and osteoporosis or Harris Hip Score; however, THA with or without the use of screws might be related to bone sclerosis in the C1 region.

Conclusion

Currently, limited evidence shows that the use of screws during THA may not improve cup stability.

Foot drop following primary total hip arthroplasty

INTRODUCTION

Foot drop is a potentially debilitating complication following injury to the sciatic nerve during primary total hip arthroplasty (THA). The aim of this study was to determine the incidence, risk factors and outcome of this complication within one large surgical practice.

METHODS

We analysed the records of 10,624 primary THAs carried out between January 1993 and November 2017 using a posterior approach. All were under the care of the senior author.

RESULTS

Overall, there were 47 cases (0.44%) of foot drop, but over time the incidence dropped from 0.6% to 0.3% (p = 0.033). Preoperative protrusio acetabulae (p < 0.001), female sex (p < 0.001) and junior grade of surgeon (p < 0.009) were all significant risk factors. In this series, dysplasia was not a risk factor. 1 year postoperatively, 25 (53.2%) had complete recovery, 12 (25.5%) had ongoing sensory deficit but normal power, and 10 (21.3%) had a residual sensory-motor deficit.

CONCLUSION

Take home message:- In this series, protrusio acetabulae, female sex and junior grade of surgeon were significant risk factors for foot drop following primary THA.

External Iliac Artery Laceration Caused by Hip Prosthesis Migration

Hip arthroplasty is a common and safe intervention in orthopedic surgery. However, the proximity of this joint to large vessels makes the occurrence of vascular injury a rare but serious and possibly lethal complication of this surgical technique. Acute vascular injuries in the context of a hip arthroplasty have variable etiologies and clinical presentations, and are more common in revision surgeries and in situations of medial intrapelvic migration and of chronic infection of the hip prosthesis. In the present article, the authors present a case of acute and late major vascular complication in the context of hip arthroplasty revision. The patient developed an acute laceration of the external iliac artery caused by chronic and progressive medial intrapelvic acetabular migration of the hip prosthesis associated with chronic infection.

Effect of surgical approach for contralateral side hip arthroplasty in below knee amputees: a retrospective cohort study

Background

The gluteus medius muscle plays a very important role in the stability of the gait, especially in patients with amputation of the lower limbs. Therefore, choosing the appropriate type of approach for hip arthroplasty is very important. Hence, this study aimed to compare the outcomes and complications between the anterolateral approach (ALA) and posterior approach (PA) for hip arthroplasty in patients with contralateral below knee amputation.

Methods

From January 1999 to November 2014, 67 patients who underwent hip arthroplasty with contralateral below knee amputation were retrospectively analyzed. The study subjects were divided into two groups: the PA group (33 cases) and the ALA group (34 cases). The results of the clinical functional recovery with Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Harris Hip Score, and activity of daily living scale were compared between the two groups. During the follow-up period, complications related to gait such as fall, dislocation, and periprosthetic fractures (PPFs) were investigated.

Results

The Harris Hip Score (p = 0.024) and the activity of the daily living scale (p = 0.043) of the ALA group were significantly lower at 3 months compared to the PA group, but no significant difference was observed between the two groups from 6 months postoperatively to the last follow-up. The WOMAC score was not significantly different between the two groups. Within 3 months after surgery, falls occurred in 3 cases in the PA group and in 11 cases in the ALA group (p = 0.019) Dislocation and PPF were caused by prosthesis-related trauma. Two dislocations and 1 PPF occurred 8 years postoperatively in the PA group. PPF occurred in 3 patients in the ALA group, of which 2 occurred within 3 months after surgery.

Conclusion

Orthopedic surgeons should pay particular attention in patients with hip arthroplasty on the contralateral side hip who had below knee amputation because functional recovery is delayed until 3 months after ALA compared with PA.

Risk Factors for the Development of Nerve Palsy Following Primary Total Hip Arthroplasty

Background:

Nerve palsy following total hip arthroplasty (THA) is a complication that worsens the functional prognosis. The present study analyzed the risk factors of nerve palsy following THA.

Methods:

The subjects of this study included 6,123 cases in which primary THA was performed under spinal anesthesia with cementless implants used in the posterolateral approach.

Results:

Fourteen cases (0.22%) developed nerve palsy following THA, all of which involved palsy of the entire peroneal nerve region. The diagnoses included osteoarthritis due to subluxation (n=6), complete hip dislocation (n=3), osteonecrosis of the femoral head (n=2), primary osteoarthritis (n=1), osteoarthritis due to trauma (n=1), and multiple osteochondromatosis (n=1). Recovery from nerve palsy was confirmed in 10 cases; the longest recovery period was three years. A univariate analysis revealed significant differences in the osteoarthritis due to subluxation, osteonecrosis of the femoral head, complete hip dislocation, body weight and body mass index. However, none of the factors remained significant in multivariate analysis. Peroneal (ischiadic) nerve palsy following THA occurred in patients with osteonecrosis of the femoral head, complete hip dislocation, low body weight and a low body mass index. However, there were no cases of nerve palsy after the introduction of THA combined with shortening osteotomy of the femur for complete hip dislocation. patients.

Conclusion:

It is necessary to pay attention to direct pressure in cases of lower body weight and lower BMI because compression of the sciatic nerve during surgery and compression of the fibular head are considered to be risk factors.

Acute thrombotic occlusion after total knee arthroplasty: Role of endovascular management

AIM

Acute arterial occlusions after total knee arthroplasty (TKA) are rare but very serious complication. We present a series of 9 patients who underwent endovascular recanalisation for acute thrombotic occlusion following TKA in our institution. The present series determine the importance of early diagnosis and role of early intervention for good clinical outcome in these cases.

METHODS

From 2013 to 2016, a total of 9 patients (3 male and 6 female) presented with acute popliteal thrombosis following TKA. All the patients underwent endovascular procedure. Clinical presentation, procedural details and clinical outcome was discussed.

RESULTS

Technical success is achieved in all the cases. A combination of clot lysis, thromboaspiration and balloon angioplasty was used. 8 patients had successful clinical outcome. One patient underwent amputation despite good recanalisation.

CONCLUSION

High degree suspicion with careful monitoring in the postoperative period is needed to identify the problem at the earliest, and early diagnosis with recanalisation within 6 h is the key to limb salvage in these patients.

Total hip arthroplasty: a still evolving technique

It has been advocated that total hip arthroplasty (THA) is probably the most successful surgical intervention performed in Medicine. In the 1960s, Sir John Charnley not only introduced, but also modified and improved the technique of cemented arthroplasties. The concepts on biological fixation established by Pillar and Galante served as the foundation for the development of uncemented implants that are now used worldwide. Currently, THA is a worldwide widespread surgery performed on millions of people. However, keeping abreast of the large number of information available on these procedures, especially on implant fixation, designs, different tribological pairings, and the long-term results can be challenging at times. This article is a brief update on the main aspects of THA.

Phlegmasia cerulea dolens and external iliac vein disruption after revision total hip arthroplasty

We present a unique case of phlegmasia cerulea dolens and compartment syndrome secondary to external iliac vein disruption after revision total hip arthroplasty. To our knowledge, this complication has not yet been described following revision total hip arthroplasty. We conclude that although vascular complications are fortunately rare after hip arthroplasty, they can have significant morbidity and mortality. Surgeons should have a thorough understanding of pelvic and hip anatomy for screw and retractor placement and know how to appropriately and expeditiously manage vascular complications should they occur.

Screw-hole clusters in acetabular cups: a morphological study of optimal positioning of screw-holes

BACKGROUND

Rigid and safe transacetabular screw fixation in total hip arthroplasty (THA) is achieved by pursuing deeper bone stock and avoiding injuries to the neurovascular structures, but these efforts can be restricted by the distribution of screw-holes on cups by the manufacturer. We therefore tried to determine: (i) optimal screw-hole positions on cups to allow anatomical placement of screws; (ii) rationality of the basic 3-screw-hole cluster on commercial cups; and (iii) the optimum method for placing commercial cups in accordance with acetabular anatomy.

METHODS

Periacetabular osseous structure of 64 hips and arterial structures of 50 hips were three-dimensionally reconstructed. Simulated transacetabular screw fixation during THA was performed in these hips with 3 different screw lengths (15, 25, and 35 mm) to define deeper and safer screw trajectories. Screw-hole locations of 7 commercially available cups were measured and matched with the periacetabular anatomy.

RESULTS

When the cup was placed into the acetabulum at 45° of abduction and 20° of anteversion, the optimal locations of 2 screw-holes on the cups were at 30° and 64° of latitude, with a 35° separation angle. The inversetriangle distribution pattern was safer than the triangle pattern in basic 3-screw-hole-cluster cups. When placing the commercial cups, 5°-10° of anterior rotation can be added to allow better screw trajectories.

CONCLUSIONS

Our study determined optimal screw-hole positions and their distribution pattern on cups. We describe methods to place the commercial cups that are not designed according to acetabular anatomy.

Possible Vascular Injury Due to Screw Eccentricity in Minimally Invasive Total Hip Arthroplasty

BACKGROUND

Vascular injury during minimally invasive total hip arthroplasty (THA) is uncommon, yet a well-recognized and serious issue. It emerges because of non-visibility of vascular structures proximal to the pelvic bone during reaming, drilling holes, and fixing of screws. Numerous studies have found that screw fixation during cementless THA is beneficial for the initial stability of cup; yet, no anatomical guidelines support angular eccentric screw fixation.

MATERIALS AND METHODS

In this study, we obtained the pelvic arterial-phase computed tomographic data of thirty eight humans and reconstructed the three-dimensional models of osseous and vessel structures. We performed the surgical simulation to fix these structures with cementless cups and screws with angular eccentricities.

RESULTS

The effect of screw eccentricities (angular eccentricities of ±17° and ±34°) on the vascular injury was determined. Measurement between screw and adjoining vessels was performed and analyzed statistically to ascertain a comparative risk study for blood vessels that are not visible during surgery.

CONCLUSION

Authors similarly discussed the significant absence of appreciation of quadrant systems proposed by Wasielewski et al. on eccentric screws. Adjustment of quadrant systems provided by Wasielewski et al. is required for acetabular implants with eccentric holes for fixation of acetabular screws.

Late screw perforation of external iliac artery following acetabular revision. A simple solution for a rare complication

Vascular lesions, although quite rare, are one of the most devastating complications in the context of a hip prosthesis. Therefore, the correct diagnosis is crucial to prevent irreversible damage to the patient. The authors present the case of a 70-year-old Caucasian woman with an ischemic lower limb as consequence of a late perforation of external iliac artery due to an acetabular screw. The issue was resolved by simply cutting part of the screw, avoiding other surgical options that would be much more aggressive for the patient. Careful clinical evaluation allowed for a correct diagnosis and a timely creative treatment, preventing further consequences to the patient.

Neurolysis for the treatment of sciatic nerve palsy associated with total hip arthroplasty

Sciatic nerve palsy following total hip arthroplasty (THA) is a relatively rare yet potentially devastating complication. The purpose of this case series was to report the results of patients with a sciatic nerve palsy who presented between 2000 and 2010, following primary and revision THA and were treated with neurolysis. A retrospective review was made of 12 patients (eight women and four men), with sciatic nerve palsy following THA. The mean age of the patients was 62.7 years (50 to 72; standard deviation 6.9). They underwent interfascicular neurolysis for sciatic nerve palsy, after failing a trial of non-operative treatment for a minimum of six months. Following surgery, a statistically and clinically significant improvement in motor function was seen in all patients. The mean peroneal nerve score function improved from 0.42 (0 to 3) to 3 (1 to 5) (p < 0.001). The mean tibial nerve motor function score improved from 1.75 (1 to 4) to 3.92 (3 to 5) (p = 0.02).The mean improvement in sensory function was a clinically negligible 1 out of 5 in all patients. In total, 11 patients reported improvement in their pain following surgery. We conclude that neurolysis of the sciatic nerve has a favourable prognosis in patients with a sciatic nerve palsy following THA. Our findings suggest that surgery should not be delayed for > 12 months following injury.

Internal iliac artery pseudoaneurysm in primary total hip arthroplasty

Vascular injury is one of the rare complications of primary total hip arthroplasty (THA). We report an unusual case of lobulated pseudoaneurysm arising from one of the branches of the left internal iliac artery during acetabulum preparation in THA, which was successfully treated with coil embolization and multidisciplinary care. After 6 years follow up, patient did not have any symptoms related to the hip replacement. We recommend that surgeons should be extremely cautious while drilling medial wall of the acetabulum for depth assessment. Aggressive multidisciplinary approach, including possible support from an interventional radiologist is required for the treatment of such vascular injuries.

Severe vascular complications and intervention following elective total hip and knee replacement: A 16-year retrospective analysis

INTRODUCTION

Iatrogenic vascular injuries associated with elective orthopaedic joint procedures are relatively rare, however when they do occur they carry a risk of significant morbidity and mortality. The aim of this study was to investigate the incidence of vascular complications and resultant need for specialist intervention following elective total hip replacement (THR) and total knee replacement(TKR).

METHODS

This was a retrospective analysis of prospectively collected data. The primary outcome measure was vascular complication requiring an interventional radiology procedures or vascular surgery. As a secondary outcome measure postoperative Modified Knee Society Scores and Harris Hip Scores were analysed to assess long term clinical outcome.

RESULTS

Six cases of vascular injury requiring specialist intervention were identified. From 2073 total TKRs there were one cases of popliteal artery injury, one case of venous injury and two case of lateral geniculate artery injury (0.19%). From 1601 THRs there were two cases (0.12%) of arterial injury. All patients were treated successfully by a vascular surgeon or an interventional radiologist. Patient outcome varied considerably with the poorest results seen in the THR group.

CONCLUSIONS

Iatrogenic vascular complications following elective THR and TKR carry a risk of significant morbidity and mortality. It is important that surgeons and trainees performing these procedures are conscious of these risks and able to identify vascular injuries promptly when they occur. Detailed preoperative assessment, an awareness of anatomical variants and close liaison with a vascular surgeon may all help to reduce the number and severity of adverse outcomes.

[Blood vessel and nerve damage in total hip arthroplasty]

Blood vessel and nerve damage are uncommon complications in total hip arthroplasty (THA). With an incidence between 0.1 and 0.2 % in primary THA these complications are rare but can be serious with a high mortality risk. The individual risk is determined by multiple factors depending on the surgeon's skills, the number of previous surgeries and the approach itself. The anatomy of the defect is an essential risk factor. Some procedures, such as the use of screws for cup fixation are associated with a higher risk of vascular and neural damage. The acetabular quadrant system of the hip as described by Wasielewski et al. is a useful tool to visualize the neurovascular anatomy of the hip, to detect the safe zone and subsequently prevent complications. Sciatic nerve palsy after total hip replacement is the most common nerve damage followed by femoral nerve damage. Previous surgery, a posterior approach and excessive leg extension are the most common risk factors for nerve damage. In order to diagnose nerve palsy after orthopedic surgery an electromyogram can be of use to assess the extent and prognosis. This article focuses on vascular and neural complications after total hip arthroplasty and the options for diagnosis, treatment and prevention.

A case of late iliac arterial thrombosis due to component migration after revision total hip arthroplasty

Although vascular injuries associated with primary and revision total hip arthroplasty are infrequent, these complications can have devastating effects that can lead to morbidity and even mortality. A few previous reports have described embolic distal limb ischemia secondary to a failed and migrated acetabular implant in discontinuity with the pelvis. We present a rare case in which a support ring from a failed and migrated acetabular cage construct led to injury of the common femoral artery. The patient developed acute thrombotic occlusion leading to distal extremity ischemia even after oral anticoagulant therapy. The patient was treated with embolectomy with a Fogarty catheter, replacement of the injured common femoral artery with an InteRing 8 mm, and removal of the offending hardware. Recognition of the risks associated with failed and migrated components is important to prevent this complication for cardiologists as well as orthopedic surgeons. <Learning objective: Although vascular injuries associated with primary and revision total hip arthroplasty are infrequent, these complications can have devastating effects that can lead to morbidity and even mortality. Recognition of the risks associated with failed and migrated components is important to prevent this complication for cardiologists as well as orthopedic surgeons.>.

The impact of leg length discrepancy on patient satisfaction and functional outcome following total hip arthroplasty

A series of 191 patients undergoing THA with a standardised stem were studied. The effect of leg length discrepancy (LLD) on patient function (Oxford Hip Score), health measures (Short Form 12) and satisfaction (Self-Administered Patient Satisfaction Scale) at a mean 3.8 years of follow up (range 3.3 to 4.9) is reported. 8.9% of cases had shortening, 0.5% no LLD and 90.6% had lengthening. In 21.5% the LLD was more than 10mm, in 37.1% 5-10mm, and in 40.9% 0-5mm. There was no significant difference in patient reported outcome measures (PROMs) according to LLD. Correlation of recorded measurements between multiple observers was excellent (0.93). LLD following total hip arthroplasty remains common but in this series, was not correlated with PROMs.

[Lower limb paresis after total hip arthroplasty. A rare differential diagnosis]

We report on a case of complex nerve damage during total hip arthroplasty. The most severe clinical symptom was proximal leg paresis with diffuse sensory loss. There was an extensive causal Iliopsoas hematoma which developed during the postoperative rehabilitation under therapeutic anticoagulation for atrial fibrillation. An iliopsoas hematoma with subsequent neurological deficits are rare events in the field of hip arthroplasty and a literature review is provided. The treatment of retroperitoneal hemorrhage is controversial but in most instances a conservative approach is favored. The prognosis of neurological damage is sobering as only 20 % of victims are expected to achieve complete restitution.

Conversion of arthrodesis to total hip arthroplasty: clinical outcome, complications, and prognostic factors of 21 consecutive cases

BACKGROUND

Although the results of hip arthrodesis compare favorably with those of total hip arthroplasty (THA) in younger patients, long-term consequences such as osteoarthritis of the neighboring joints may necessitate conversion of the arthrodesis to THA.

QUESTIONS/PURPOSES

The purpose of the present study is to assess mid-term clinical outcome and self-perceived improvement in patients who underwent conversion at our department. Secondary aims were incidence of complications and association between patient characteristics and characteristics of the fusions with the outcome of the procedure.

PATIENTS AND METHODS

The study sample comprised 21 cases in 20 patients. Minimum follow-up was 3 years (mean, 8 ± 6.5 years) in 20 cases. Thirteen patients had surgical hip fusions and 7 (8 hips) had nonsurgical fusions. Mean age at the time of conversion was 58.5 years.

RESULTS

Nineteen out of 21 cases had functioning implants at the latest follow-up visit. According to the Merle d'Aubigné scale, outcome was considered excellent, very good, or good in 15 cases. Lower back pain was reduced in all patients. All but two patients were satisfied after the conversion. The main complications observed included incomplete removal of bone block, intra-operative fractures, dislocation and damage to the femoral artery. Time to conversion and type of fusion had no significant correlation with the clinical outcome.

CONCLUSIONS

Conversion THA is a challenging but successful procedure according to the mid-term clinical outcome observed. Our study suggests that, prognostic factors should be used with caution when establishing indications and post-surgical expectations.

Internal iliac artery injury and total hip arthroplasty: discovery after 10 years

Delayed presentation of iliac artery injury by acetabular screw. Screw removal at liner revision of a 10-year-old uncemented acetabular shell resulted in unexpected catastrophic blood loss. Replacing the screw prevented further hemorrhage, and investigation revealed internal iliac artery injury caused by the screw. This was treated successfully by bypass grafting. Careful review of preoperative imaging should aim to identify those at risk and requiring further imaging before undergoing revision surgery.

Cup press fit in uncemented THA depends on sex, acetabular shape, and surgical technique

BACKGROUND

Uncemented press-fit cups provide bone fixation in primary THA, but the use of screws is sometimes necessary to achieve primary stability of the socket. However, it is unclear whether and when screws should be used.

QUESTION/PURPOSES

We analyzed the factors related to screw use with a press-fit uncemented cup and assessed whether screw use is associated with the same rates of loosening and revision as a press-fit technique.

METHODS

We retrospectively reviewed 248 patients who underwent THA using the same prosthetic design. Eighty-eight hips had screws to achieve primary cup fixation (Group 1), and 189 did not (Group 2). Mean age was 50 years (range, 14-73 years). We analyzed factors related to the patient, acetabular type, and reconstruction of the rotation center of the hip. Minimum followup was 5 years (mean, 8.9 years; range, 5-12 years).

RESULTS

We found higher screw use in women, patients with less physical activity, Acetabular Types A or C, and a distance from the center of the prosthetic femoral head to the normal center of rotation of more than 3 mm. There were four revisions in Group 1 and five in Group 2. Eight hips had radiographic loosening in Group 1 and nine in Group 2. Cups with a postoperative abduction angle of more than 50° had a higher risk for loosening.

CONCLUSIONS

Press fit was achieved less frequently in women and patients with Acetabular Types A or C and less physical activity; a closer distance to the normal center of rotation decreased screw use. Screw use to augment fixation achieved survival similar to that of a press-fit cup.

LEVEL OF EVIDENCE

Level II, prognostic study. See Instructions for Authors for a complete description of levels of evidence.

Patient-reported complications after elective joint replacement surgery: are they correct?

Using general practitioner records and hospital notes and through direct telephone conversation with patients, we investigated the accuracy of nine patient-reported complications gathered from a self-completed questionnaire after elective joint replacement surgery of the hip and knee. A total of 402 post-discharge complications were reported after 8546 elective operations that were undertaken within a three-year period. These were reported by 136 men and 240 women with a mean age of 71.8 years (34 to 93). A total of 319 reported complications (79.4%; 95% confidence interval 75.4 to 83.3) were confirmed to be correct. High rates of correct reporting were demonstrated for infection (94.5%) and the need for further surgery (100%), whereas the rates of reporting deep-vein thrombosis (DVT), pulmonary embolism, myocardial infarction and stroke were lower (75% to 84.2%). Dislocation, peri-prosthetic fractures and nerve palsy had modest rates of correct reporting (36% to 57.1%). More patients who had knee surgery delivered incorrect reports of dislocation (p = 0.001) and DVT (p = 0.013). Despite these variations, it appears that post-operative complications may form part of a larger patient-reported outcome programme after elective joint replacement surgery.

[Nerve lesions after minimally invasive total hip arthroplasty]

Although there is no clear evidence, minimally invasive hip arthroplasty seems to be associated with slightly higher complication rates compared to standard procedures. Major nerve palsy is one of the least common but most distressing complications. The key for minimizing the incidence of nerve lesions is to analyze preoperative risk factors, accurate knowledge of the anatomy and minimally invasive techniques. Once clinical signs of nerve injury are evident, the first diagnostic steps are localization of the lesion and quantification of the damage pattern. Therefore, clinical assessment of the neurological deficits should be performed as soon as possible. Apart from rare cases of isolated transient conduction blockade or complete transection, the damage pattern is mostly combined. Thus, there can be evidence for dysfunction of nerve conduction (neuropraxia) and structural nerve damage (axonotmesis or neurotmesis) simultaneously. Because the earliest signs of denervation are detectable via electromyography after 1 week, it is not possible to make any reliable prognosis within the first days after nerve injury using electrophysiological methods. This review article should serve as a guideline for prevention, diagnostics and therapy of neural lesions in minimally invasive hip arthroplasty.

A late vascular complication due to component migration after revision total hip arthroplasty

Although vascular injuries associated with primary and revision total hip arthroplasty are infrequent, these complications can have devastating effects that can lead to morbidity and even mortality. No previous reports have described embolic distal limb ischemia secondary to a failed and migrated acetabular implant in discontinuity with the pelvis. We present a novel case in which a screw from a failed and migrated acetabular cage construct led to injury of the superficial femoral artery. While awaiting the construction of a custom prosthesis, the patient developed thromboembolism leading to distal extremity ischemia. The patient was treated with thrombolytic therapy, anticoagulation, removal of the offending hardware, forefoot amputation, and later hip reconstruction. Recognition of the risks associated with failed and migrated components may prevent this complication in the future.

Evaluation of intra-pelvic screw position prior to revision total hip arthroplasty--a report of 2 cases

Neurovascular injury during total hip revision arthroplasty is rare, but potentially catastrophic. We report two patients requiring revision total hip arthroplasty with intrapelvic screw tips located close to the iliac artery. The screw tips were separated from artery by a retroperitoneal exposure prior to revision surgery. Assessment of screw position by computed tomography (CT) is important prior to revision total hip arthroplasty.

Total hip arthroplasty revision in case of intra-pelvic cup migration: designing a surgical strategy

Intrapelvic acetabular cup migration is a rare but serious complication, which can occur after cup loosening following total hip arthroplasty. To make safe intrapelvic implant removal, several principles must be respected: identification of potential risks with a thorough preoperative workup, preoperative planing of a surgical strategy for removing protruding hardware without injuring noble anatomical structures, preserving muscle and bone stock, pelvic anatomy reconstruction (including, as needed, osteosynthesis of the pelvis), and prosthetic components selection correcting any length discrepancy. Preoperative assessment is based on a complete radiological workup, angio-CT, as well as studies searching for signs of inflammation (blood workup and joint aspiration). All cases of intrapelvic migration of an acetabular component do not systematically command a subperitoneal approach. The presence of some residual bone shell, an intrapelvic foreign body, or a path deviation from normal in a vascular bundle or an ureter must be analyzed before deciding on the approach. The potential problems managing this mode of loosening event are a reminder for the need of periodical total hip arthroplasty follow-up. This regular monitoring helps preventing complications sometimes life threatening.

The value of immediate preoperative vascular examination in an at-risk patient for total knee arthroplasty

Arterial complications associated with total knee arthroplasty (TKA), although infrequent, may be associated with the following sequelae: infection, limb loss, and rarely, death. When revascularization is undertaken in the postoperative setting, additional complications may be encountered including postischemic reperfusion injury necessitating prophylactic fasciotomies. The end result is a prolonged postoperative course leading to worse functional outcome. A preoperative history and physical examination performed by the orthopedic surgeon can determine if the patient is at increased risk for vascular complications and whether the at-risk limb can withstand the stress of the operation. Consideration should be given to obtaining ankle-brachial indexes in this patient population, noting that arterial calcification may elevate the value. This article presents a case of an immediate preoperative vascular examination, performed at the time of surgical site marking, in an at-risk patient prior to TKA. We detail the clinical course of a patient with peripheral vascular disease and indwelling superficial femoral artery stent, who developed stent thrombosis in the 2-week period between his last clinic visit and date of surgery, with no change in symptoms. This restenosis was detected on routine preoperative physical examination and resulted in cancellation of the TKA in the preoperative area, allowing the patient to undergo emergent revascularization. We emphasize the importance of an immediate preoperative vascular examination in the setting of TKA and provide a comprehensive review of the literature with guidelines on the perioperative management of antiplatelet agents and appropriate use of the tourniquet.

Incidence of lateral femoral cutaneous nerve neuropraxia after anterior approach hip arthroplasty

BACKGROUND

Although injury to the lateral femoral cutaneous nerve (LFCN) is a known complication of anterior approaches to the hip and pelvis, no study has quantified its' incidence in anterior arthroplasty procedures.

QUESTIONS/PURPOSES

We therefore defined the incidence, functional impact, and natural history of LFCN neuropraxia after an anterior approach for both hip resurfacing (HR) and primary total hip arthroplasty (THA).

METHODS

We followed 132 patients who underwent an anterior hip approach (55 THA; 77 HR). We administered self-reported questionnaires for sensory deficits of LFCN, neuropathic pain score (DN4), visual analog scale, as well as SF-12, UCLA, and WOMAC scores at one year postoperatively. A subset of 60 patients (30 THA; 30 HR) was evaluated at two time intervals.

RESULTS

One hundred seven patients (81%) reported LFCN neuropraxia with a mean severity score of 2.32/10 and a mean DN4 score of 2.42/10. Hip resurfacing had a higher incidence of neuropraxia as compared with THA: 91% versus 67%, respectively. No functional limitations were reported on SF-12, WOMAC, or UCLA scores. Of the subset of 60 patients followed over an average of 12 months, 53 (88%) reported neuropraxia at the first followup interval with only three (6%) having complete resolution at second followup. Improvement in DN4 scores was observed over time: 3.6 versus 2.5, respectively.

CONCLUSIONS

Although LFCN neuropraxia was a frequent complication after anterior approach THA, it did not lead to functional limitations in our patients. A decrease in symptoms occurred over time but only a small number of patients reported complete resolution.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Late small intestine perforation after cementless total hip arthroplasty

We report a case of late small intestine perforation by an acetabular cup fixation screw after total hip arthroplasty (THA). A 79-year-old-woman underwent THA for hip osteoarthritis 13 years previously at another hospital. Although the acetabular cup fixation screw protruded into the pelvis, she had no symptoms. She later presented with peritonitis and was admitted to the hospital and prescribed antibiotic therapy. Computed tomography showed that the screw was adjacent to the intestine and was the likely cause of her peritonitis. After the peritonitis healed, she was referred to our hospital for surgical treatment of the screw. During laparotomy, we performed a resection of the intra-pelvic portion of the screw. The screw perforated the small intestine, so a small intestinal resection was also performed. The patient had an uneventful recovery.

Which approach for total hip arthroplasty: anterolateral or posterior?

The best approach to use when performing THA is controversial. We did a prospective, nonrandomized multicenter study of 1089 THAs to evaluate patient-centered hip scores and dislocation and revision rates when comparing anterolateral and posterior hip approaches at 5 years' followup. Patients were divided into two groups depending on which surgical approach was used: anterolateral or posterior. The primary outcome measure was change in Oxford hip score. At 5 years, there were no differences in change in Oxford hip score and in dislocation or revision rates between the groups.

LEVEL OF EVIDENCE

Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Vascular injuries after total joint arthroplasty

Vascular injuries, although highly feared, can occur after total joint arthroplasty, often resulting in legal suits. This study evaluates the circumstances related to vascular injuries after joint arthroplasty. Using prospectively collected data on 13,517 patients undergoing total joint arthroplasty at our institution, 16 (0.1%) vascular injuries were identified. Eleven injuries occurred after total knee arthroplasty (TKA) and 5 after total hip arthroplasty (THA). Indirect injury was the most common mechanism in TKA. In contrast, direct injury was most prevalent in THA. One patient died of complications related to vascular injury. Of 16 patients, 8 (50%) had launched a legal suit against the operating surgeon. There appears to be no further specific measure that can be taken to absolutely avoid this complication. Patient awareness regarding this real problem may play a role in defraying the high likelihood of legal suits associated with this complication.

Comparison of performance of conventional and minimally invasive surgery acetabular reamers

Acetabular reaming in minimally invasive surgery can be done using a newly designed minimally invasive reamer. The new minimally invasive reamer is narrower and chamfered, which results in two sharp edges. This design may result in acetabular cavities with less ideal spheres than those achieved with conventional reaming. We compared the acetabular shapes in nine pairs of cadaver acetabula. Minimally invasive reaming was performed in one acetabulum of each pair, and conventional reaming was performed on the contralateral side. A new digitizing technique, optical three-dimensional scanning, was applied to the reamed acetabula to determine the reamers' performance. Best-fit spheres were calculated for the reamed cavities, and all reamers were measured for exact dimensions. There were small deviations between the diameters of the reamer and the reamed cavity for the minimally invasive (mean, 0.1 mm; standard deviation, 0.5 mm) and conventional (mean, 0.3 mm; standard deviation, 0.4 mm) reamers. There were no significant differences between minimally invasive and conventional reaming. The mean differences between the reamer domes and the measured values showed a discrepancy of 2.2 mm (standard deviation, 0.08 mm) in the minimally invasive surgery group and 2.8 mm (standard deviation, 0.09 mm) in the conventional group. Although the acetabular reamer design has been modified, there were no significant differences in the acetabular shapes after minimally invasive or conventional reaming.

LEVEL OF EVIDENCE

Therapeutic Study, Level II (prospective comparative study with no statistically significant difference). See the Guidelines for Authors for a complete description of levels of evidence.

Postarthroplasty ???Palsy??? and Systemic Neuropathy

Postarthroplasty palsy, occurrence of dysfunction of the sciatic or peroneal nerve after total joint replacement of the hip or knee, is a complication that remains poorly understood. Characteristics of a series of 24 patients with postarthroplasty palsy are reviewed, with the finding that, overall, 58.4% of the patients had an underlying peripheral neuropathy. The role of this neuropathy predisposing the arthroplasty patient to stretch/traction injury is discussed and should be emphasized as a risk factor prior to surgery and should influence the surgeon's intraoperative use of force during the arthroplasty procedure. This clinical problem is addressed from the perspective of peripheral nerve surgery, with an algorithm suggested for its management. The algorithm suggests that if a peroneal palsy is still present at 3 months after an arthroplasty and neurosensory testing fails to demonstrate a sensory reinnervation pattern in the territories of the deep or superficial peroneal nerve, then surgical neurolysis of the common peroneal nerve is indicated.

Dépose par laparotomie des composants d’une prothèse totale de hanche compliquée de migration intra-pelvienne avec complication urinaire

We present the first report of transabdominal removal of femoral and acetabular components of a severely loosened hip prosthesis protruding into the pelvis. In a 73-year-old woman post-operative development of urinary tract complications emphasize importance of careful assessment of the prosthetic relations with the vascular and nervous structures as well as pelvic organs before removal of the hip prosthesis. Angio-computed tomography is the most contributive exploration to assess vascular relations. In patients with particular clinical presentations or with threatened structures in the vicinity of the prosthesis, this examination must be completed by complementary opacifications (urinary and gastrointestinal tracts, joints). Ureteral catheterization may be needed if the structures are close or if there is a suspected modification of the urinary tract (retraction, mass effect). In present case, we did not opacify the urinary tract before laparatomy despite the presence of urinary signs preoperatively. A suspected ureterovaginal fistula was discovered. But they where also a ureteral lesions which can result from difficult dissection in contact with infected tissues. In this patient, urinary complications led to nephrectomy after temporary pyelostomy for urine bypass. At last follow-up, the urinary tract infection was controlled but reimplantation was not attempted because of insulin dependent diabetes mellitus and poor general condition. The spontaneous course of this infection with prosthesis loosening recalls the importance of regular surveillance of total hip replacements.