Lag Screw Cut-out Research Articles

Unusual Case of Osteosynthesis Failure in a Hip Fracture: Side-Plate Pull-Out

Osteoporotic hip fractures are common in our setting. Poor bone quality favors complications of the osteosynthesis procedures used to treat these patients. Lag-screw cut-out through the femoral head is not uncommon (2%), but pull-out of side plate screws is very unusual. We present the case of a patient with a stable osteoporotic fracture treated by osteosynthesis using a four-hole plate, who presented with a pull-out following a low-energy fall.

Risk factors in cutout of sliding hip screw in intertrochanteric fractures: an evaluation of 937 patients

The aim of this study was designed to assess the risk factors of lag-screw cutout in the treatment of intertrochanteric fracture with a dynamic hip screw (DHS). From 2003 to 2007, 1,150 patients who had acute unilateral intertrochanteric fractures of the femur were enrolled to the study. All fractures were managed by closed reduction and internal fixation with 135° DHS devices. Patient demographics, fracture patterns, reduction and fixation and perioperative course parameters were all recorded. The follow-up period was 38 months on average (range 16-60 months). Finally, 937 patients were available for evaluation of final results in which we focused on lag-screw cutout. Excluding complications not related to screw position, 64 patients (6.8%) with screw cutout were encountered, and the remaining 873 patients had uneventful union, with the average union time of 17.5 weeks (range15-24 weeks). Upon analysis with logistic regression, the tip-apex distance (TAD) was shown to be the most important predictive factor for cutout, followed by screw position, fracture pattern, reduction and patient age. In order to decrease the risk of lag-screw cutout, it is important to ensure good fracture reduction and to place the lag screw in either the middle/middle or inferior/middle position with appropriate TAD.

Tip-apex distance of intramedullary devices as a predictor of cut-out failure in the treatment of peritrochanteric elderly hip fractures

A tip-apex distance (TAD) of greater than 25 mm has been shown to be an accurate predictor of lag screw cut-out when sliding hip screws (SHS) are used to treat peritrochanteric (PT) hip fractures. The purpose of this study was to determine which factors, including TAD, correlated with successful clinical outcomes of PT hip fractures surgically treated with intramedullary (IM) devices. A total of 192 patients were included in this retrospective study. The TAD values of this cohort were radiographically analysed at a mean follow-up of 13 months. This was correlated with limited functional status and the rate of revision for implant failure or inability to achieve fracture union. Only 82 patients had adequate follow-up to fracture union or definitive failure. There were 46 intertrochanteric (IT) hip fractures and 36 subtrochanteric (ST) fractures. Overall, seven patients (8.5%) went on to experience lag screw cut-out. The average TAD of the patients who did not cut-out was 18 mm, compared to 38 mm for those who did (p = 0.012). All patients who cut-out had IT fractures (p = 0.017). The percentage of cut-outs correlated directly to both the severity of IT fractures and the TAD. Using a cutoff of 25 mm there was a statistically significant difference in the incidence of lag screw cut-out (p < 0.001). As in sliding hip screws, surgeons should strive for a TAD less than 25 mm when using IM devices in the treatment of PT hip fractures to help avoid lag screw cut-out.

The importance of surgical education in the accuracy of implant placement during hip fracture fixation

BackgroundStudies have found that tip apex distance (TAD) is the strongest independent predictor of lag screw cut-out following hip fracture fixation. The objective of this study was to understand the importance of introducing the concept of TAD to surgeons. The null hypothesis was that there were no differences between fractures fixed before awareness of TAD compared with fractures fixed after awareness of TAD.Materials and MethodsThis study involved assessing 75 consecutive radiographs retrospectively (before introduction of “tip apex distance” to surgeons) and 83 consecutive radiographs prospectively (after introduction of “tip apex distance” to surgeons). Radiographs were measured using a radiograph digitizer and software.ResultsAverage TAD in radiographs measured retrospectively was 22.6 mm compared with 9.7 mm in radiographs analysed prospectively (P ≤ 0.001). The power of this study was 97%.ConclusionThis study demonstrates that introducing the concept of “TAD” to surgeons, will improve the accuracy of lag screw placement during fixation of an extracapsular fracture. The improvements in lag screw placement will undoubted reduce cut-out of the implant post-surgery.

Postoperative implant-related complications after treatment of intertrochanteric fracture by gamma nail or by sliding hip screw: a meta-analysis

To evaluate and compare the postoperative implant-related complications after treatment of intertrochanteric fracture by gamma nail or by sliding hip screw. Literatures on randomized controlled trials (RCTs) of the postoperative implant-related complications after treatment of intertrochanteric fracture by gamma nail or by sliding hip screw published before the end of June 2007 were retrieved from Cochrane library, Medline, Embase databank, and Chinese Biomedical Database. Relevant articles were handsearched in several Chinese journals. Methodology quality of the trials was critically assessed and data on postoperative implant-related complications were extracted. The software RevMan4.2.10 provided by the Cochrane Collaboration was used for meta-analysis. 10 RCTs and 3 quasi-RCTs involving 1857 cases were included. The results of meta-analysis showed that gamma nailing significantly increased the rate of postoperative femoral shaft fractures [RR = 3.75, 95%CI (1.47, 9.55), P = 0.006]. However, there were no statistic differences in the rates of lag screw cut-out and total mechanical complications between gamma nail and sliding hip screw treatment. Compared with sliding hip screw for intertrochanteric fractures, gamma nailing can lead to higher incidence of postoperative femoral shaft fractures. Fracture stability may influence the rate of postoperative implant-related complications. Further large sample and high quality RCTs based on fracture stability are required in order to provide more sufficient and reliable evidence.

Proximal femoral nails versus sliding hip screws in treatment of intertrochanteric fractures in adults:a systematic review

Objective To compare the efficacy of proximal femoral nails (PFN) versus sliding hip screws (SHS) in the treatment of intertrochanteric fractures in adults. Methods According to Cochrane systematic review, Cochrane library, Medline, Embase and Chinese Biomedical Database were searched for randomized controlled trials (RCT) comparing PFN with SHS in the management of intertrochanteric fractures from 1996 to the end of June 2007. Furthermore, we also searched manually relevant references and Chinese orthopedic journals. Methodology quality of the trials was critically assessed and relative data were extracted.Statistical software Revman 4.2. 10 was used for data-analysis. Results Three RCTs and 1 quasi-RCT involving 458 cases were included. The results of meta-analysis showed that no statistically significant differences were found in the mean duration of surgery, mean intraoperative blood loss, mortality, post-operative femoral shaft fractures, lag screw cut-out, nonunion, reoperation and wound infection between PFN and SHS. Conclusions There is not enough evidence showing any obvious advantage of PFN fixation over SHS fixation in the treatment of intertrochanteric fractures in adults. Because the number of trials available for a systematic review is too small for a reliable estimate, large-scale and high-quality RCTs are needed to further determine the effects of PFN fixation versus SHS fixation. Key words: Hip fractures; Fracture fixation,internal; Systematic review

Proximal Femoral Nail for Treatment of Trochanteric Femoral Fractures

To report outcomes of 87 consecutive patients treated with a proximal femoral nail (PFN) for trochanteric femoral fractures. 17 men and 70 women aged 58 to 95 (mean, 85) years with trochanteric femoral fractures underwent PFN fixation using an intramedullary nail, a lag screw, and a hip pin. Fractures were classified according to the AO system; the most common fracture type was A2 (n=45), followed by A1 (n=36) and A3 (n=6). The position of the lag screw within the femoral head was measured. The lateral slide of the lag screw after fracture consolidation was measured by comparing the immediate postoperative and final anteroposterior radiographs. 90% of lag screws were placed in an optimal position. The length of lateral slide of the lag screw in stable A1 fractures was significantly less than that in unstable A2 fractures; it was over 10 mm in 7 of 45 patients with A2 fractures. Cut-out of lag screw did not occur, suggesting that free sliding of the lag screw facilitates direct impaction between fragments. A PFN is useful for the treatment of trochanteric femoral fractures.

Encouraging Results of Treating Femoral Trochanteric Fractures With Specially Designed Double-Screw Nails

Conventional intramedullary nails for trochanteric fractures have the disadvantages of intraoperative splintering resulting from large proximal section and postoperative femoral fracture caused by stress concentration at the nail tip. The present study reports the experience of using a specially designed double-screw nail with a smaller proximal section to avoid intraoperative splintering and a longer nail shank to avoid postoperative femoral fracture. Between 2003 and 2005, 144 consecutive femoral trochanteric fractures in 143 patients with an average age of 78.2 years were treated with double-screw nails. The OTA fracture classification was 31-A1 in 51 cases, 31-A2 in 65 cases, and 31-A3 in 28 cases. Seventy-nine patients had more than one major medical disease. The operation was performed using fluoroscopic guide on the fracture table. A distal locking screw was applied in patients with 31-A2 and A3 fractures. At 1 year, 23 patients had died and 6 were lost to follow-up, leaving 114 fractures for functional evaluation. Patients with 31-A1 fractures tended to have better preoperative conditions than those with 31-A2 and A3 fractures had. The operation time and hospital stay were significantly shorter for those with 31-A1 fractures. Lag screw breakage occurred in four patients with 31-A2 and A3 fractures, and two of these also had screw backout. Another three patients had lag screw cutout. Among these seven patients, only one with screw cutout underwent revision of the fixation. All 114 fractures at 12 months had eventual union. Preoperative mobility was recovered in 35 (85%) patients with 31-A1 fractures and 45 (61%) with 31-A2 and A3 fractures. The functional recovery among patients with 31-A2 and A3 fractures was significantly worse than their preoperative condition and that of patients with 31-A1 fractures. The double-screw nail can yield acceptable treatment results for both 31-A1 and 31-A2 and A3 trochanteric fractures and is particularly useful in patients with a small proximal femur. Type 31-A1 and 31-A2 and A3 trochanteric fractures should be separately analyzed in terms of treatment planning or prognostic study.

Vissage versus enclouage gamma dans les fractures de la hanche

This is a retrospective study of 102 patients with intertrochanteric hip fractures comparing the operative results of short gamma nail™ fixation with the sliding hip screw. The average patient age in the study is 83 years (range 52–94 years) with 87% females. The transfusion requirements between the two groups did not differ but a slightly larger decrease in hemoglobin levels was seen at 48 h in the gamma nail group. In neither group were there any intra-operative fractures or infections which led to a return to the operating room. The average length of stay for both groups was identical at 6.9 days. Twenty-seven short gamma nail patients and 18 compression hip screw patients were followed for 6 months. There were no instances of cut-out in either group but the short gamma nail group had middle/middle lag screw placement on the AP and lateral views more often than the compression hip screw (50%) group at 6 months. We conclude that the short gamma nail can be used effectively for the fixation of intertrochanteric hip fractures without the occurrence of potentially devastating complications such as intraoperative femur fracture, periprosthetic fracture or lag screw cut-out.

Lag screw cut-out as a result of hip varus deformation in intertrochanteric fractures treated by Gamma nails

目的 探讨股骨转子间骨折经Gamma钉的固定后髋内翻及拉力螺钉切割脱出的原因与预防措施.方法 2002年2月～2005年12月采用Gamma钉内固定治疗174例AO/OTA分型为A2型股骨转子间骨折患者,其中A2.2型107例,A2.3型67例;闭合复位135例,开放复位39例.术后2～3 d第一次摄片检查,出院后于术后6、12、18、24周进行门诊摄片随访.结果 125例患者获3～23个月随访.发生髋内翻37例,内翻并切割脱出2例.2例均为高龄(78、92岁)、肥胖(69、74 kg)女性患者,术后1周离床部分负重行走,分别在术后3个月及7个月发现骨折部内翻,拉力螺钉切割股骨头,向后上方脱出.2例患者均采用患肢皮牵引及丁字鞋固定,10周后畸形愈合,1例将内固定全部取出,另1例因身体原因仅取出拉力螺钉.术后功能恢复不佳,远较骨折前差.结论 对于高龄、肥胖女性的A2型股骨转子间骨折,Gamma钉内固定术后不宜过早负重行走,应缩短摄片检查间隔.发现拉力螺钉在股骨头内移动或轻度骨折内翻现象时,应卧床休息,直至出现骨折愈合迹象。

The Trochanteric Nail versus the Sliding Hip Screw for Intertrochanteric Hip Fractures: A Review of 93 Cases

The trochanteric nail, a redesigned short gamma nail, (Howmedica, Rutherford, NJ) was introduced in the United States during 1998 for the treatment of intertrochanteric fractures. We retrospectively reviewed 93 patients who were treated for an intertrochanteric fracture with either a sliding hip screw (SHS) or the short trochanteric nail (TN). In all, 94% of the patients in the sliding hip screw group healed without complication. There was one case of femoral head necrosis, one lag screw cutout, and one hardware removal for pain. Eighty-nine percent of the patients in the trochanteric nail group healed without complication. There was one late fracture at the tip of the nail, three cases of lag screw cutout, and one nonunion. This study suggests that the trochanteric nail is a reasonable alternative to the sliding hip screw when used for intertrochanteric fractures, although it may be associated with higher complication rates.

Lag screws for hip fracture fixation: Evaluation of migration resistance under simulated walking

Previous mechanical studies concerning cut-out of lag screws for pertrochanteric hip fractures have relied on static or dynamic uniaxial loading regimens to induce construct failure by varus collapse and superior cut-out. However, the hip is loaded in a multiplanar, dynamic manner during normal gait. We designed a hip implant performance simulator (HIPS) system to evaluate lag screw cut-out under multiplanar loading representative of normal gait. Five surrogate pertrochanteric fracture specimens with lag screw fixation were loaded up to 20,000 cycles using a biaxial rocking motion (BRM) gait simulation protocol. Another five specimens were loaded using a standard uniaxial loading protocol. The BRM loading group exhibited combined varus collapse (5.4+/-2.9 degrees ) and backward rotation (7.2+/-2.8 degrees ). The uniaxial loading group exhibited four times less varus collapse (1.4+/-1.1 degrees ) as compared to the BRM group, and only negligible rotation. For correlation of lag screw migration in surrogate specimens to that in native bone, six human cadaveric specimens were subjected to BRM loading. The degree of varus collapse (8.5+/-7.7 degrees ) and rotation (7.2+/-6.4 degrees ) in cadaveric specimens were comparable to that in surrogate specimens, with the surrogate specimens showing significantly less variability. The results demonstrate that accounting for clinically realistic multiplanar loading vectors significantly affects implant migration, and therefore should be considered when evaluating the fixation strength of hip screw implants.

Two-hole side-plate DHS in the treatment of intertrochanteric fracture: Results and complications

We reviewed 83 intertrochanteric fractures fixed with a 135 degree dynamic hip screw (DHS) and two-hole side-plate. The mean age was 72 years. There were 13 A1.1, 24 A1.2, 16 A2.1, 29 A2.2 and 1 A2.3 fractures. Established osteoporosis was seen in 55 patients. The mean time to union was 14.5 weeks. Sixty-eight percent had minimal collapse, 24% moderate and 8% severe. Over 80% of moderate and severe collapses were associated with osteoporosis and an unstable fracture pattern. There were four failures: two from lag screw cut-out and two from pull-out of the side-plate.

Lag screws for hip fracture fixation: Evaluation of migration resistance under simulated walking

Previous mechanical studies concerning cut-out of lag screws for pertrochanteric hip fractures have relied on static or dynamic uniaxial loading regimens to induce construct failure by varus collapse and superior cut-out. However, the hip is loaded in a multiplanar, dynamic manner during normal gait. We designed a hip implant performance simulator (HIPS) system to evaluate lag screw cut-out under multiplanar loading representative of normal gait. Five surrogate pertrochanteric fracture specimens with lag screw fixation were loaded up to 20,000 cycles using a biaxial rocking motion (BRM) gait simulation protocol. Another five specimens were loaded using a standard uniaxial loading protocol. The BRM loading group exhibited combined varus collapse (5.4 ± 2.9°) and backward rotation (7.2 ± 2.8°). The uniaxial loading group exhibited four times less varus collapse (1.4 ± 1.1°) as compared to the BRM group, and only negligible rotation. For correlation of lag screw migration in surrogate specimens to that in native bone, six human cadaveric specimens were subjected to BRM loading. The degree of varus collapse (8.5 ± 7.7°) and rotation (7.2 ± 6.4°) in cadaveric specimens were comparable to that in surrogate specimens, with the surrogate specimens showing significantly less variability. The results demonstrate that accounting for clinically realistic multiplanar loading vectors significantly affects implant migration, and therefore should be considered when evaluating the fixation strength of hip screw implants.

External Fixation of Pertrochanteric Fractures

Sliding hip screw fixation is the most common surgical treatment for pertrochanteric fractures. Intramedullary hip screw fixation is another popular surgical option; however, for either sliding hip screw or intramedullary hip screw fixation, mechanical complications such as lag screw cut-out are frequent. Furthermore with these fixation techniques, the inability to restore previous hip anatomy is common. Recently, external fixation has been proposed as a suitable fixation technique for pertrochanteric fractures. The main advantages of external fixation include: minimally invasive, short operative time, limited blood loss, and maintenance of the reduction obtained at surgery. For these reasons, we evaluated the results of pertrochanteric fractures treated with external fixation after a minimum follow-up of 6 months. Ten consecutive female osteoporotic patients (age ≥ 65 years) with AO/OTA fracture type A 1 or A 2 were included in the study. Fractures were treated with Orthofix pertrochanteric fixator (OPF) with four hydroxyapatite (HA)-coated pins. The mean patient age was 82 ± 7 years. The mean operative time was 34 ± 5 min. Fixators were removed three months postoperatively. There was union in all fractures. No blood transfusions were required postoperatively. There was no pin-track infection. The mean pin-insertion torque was 1 962 ± 1 215 N/mm and the mean pin extraction torque was 2 784 ± 1 648 N/mm. These latter results indicated improved pin fixation over time (p < 0.0005). There was no significant change in fracture reduction over time since there were no differences between the femoral-neck-shaft angle at 6 months and postoperatively. This study demonstrates that external fixation is a reliable treatment option for osteoporotic pertrochanteric fractures.

Surgical Treatment of Intertrochanteric Hip Fractures With Associated Femoral Neck Fractures Using a Sliding Hip Screw

The purpose of this study was to report the results of surgical treatment of a subset of intertrochanteric fractures with posteromedial comminution and extension of the fracture line into the femoral neck using a sliding hip screw. Retrospective review. Level I county trauma center. Twenty-nine fractures (8%) with this pattern were identified from 381 intertrochanteric hip fractures treated at a single institution over a 10-year period. Nine patients were excluded (2 died, 7 had incomplete radiographic follow-up), leaving 20 patients for assessment. All fractures were treated with a sliding hip screw. Radiographs at a mean follow-up of 17 months were recorded as demonstrating: 1) fixation failure; 2) fracture union; or 3) fracture nonunion. The tip-apex distance, amount of lag screw collapse, screw position in the femoral head, and adequacy of reduction were determined. Treatment failed according to these radiographic measures in 5 of 20 (25%) fractures. Failures included fracture nonunion (1 case), lag screw cutout (2 cases), and combined nonunion/lag screw cutout (2 cases). All 5 failures had complete collapse of the lag screw, whereas 4 of the 15 successfully treated fractures had complete collapse. The amount of collapse was significantly greater for the treatment failures (mean, 38 mm) than in the successfully treated hips (mean, 20 mm). There was no significant association between treatment success or failure and tip-apex distance, lag screw position, and adequacy of reduction. We conclude that intertrochanteric hip fractures with associated femoral neck fractures should not be managed with a standard sliding hip screw.

Use of the talon hip compression screw in intertrochanteric fractures of the hip.

A retrospective analysis of a compression hip screw with four reversibly deployable talons was done. Fifty-four patients had sufficient radiographs to be included in this analysis. One-year mortality was 17% and increased to 41% by 2 years. No lag screws cut out, and postoperative slide was reduced compared with that in many published series. Three patients had revision of a failed alternate-type hip pin with the Talon hip compression screw. Previous studies showed the talons provide the definitive difference in allowing enhanced compression at the time of surgery, preventing cut-out by enhanced rotational stability, and allowing immediate postoperative weightbearing without excessive limb shortening. The failure mode of the Talon compression hip screw seems to be side-plate loosening rather than varus deformity and lag screw cut-out. The Talon compression hip screw especially is effective with weak, osteoporotic bone and in unstable, three-part and four-part fractures. A previous study showed that Talon deployment notably improved interfragment compression and torsional strength, and that engagement or penetration into or through the cortical bone at the base of the femoral head-neck junction in the inferior lag screw position was the critical technical step to maximize the talon lag screw purchase.

Prevention of Hip Lag Screw Cut-Out by Cement Augmentation: Description of a New Technique and Preliminary Clinical Results

Cement augmentation of hip lag screws to avoid cut-out displacement is classically described, along with a number of technical drawbacks. In a series of six elderly patients with hip fractures in osteoporotic bone, we illustrate catheter-assisted delivery of limited amounts of a new bisphenol-a-glycidyl dimethacrylate (bis-GMA)-based composite into hip compression screw threads, enabling significant increase in insertional torque compared with unaugmented screws. In two patients, unaugmented screws that did not initially purchase were tightened with a minimum torque of 1 N-m after augmenting with bis-GMA-based composite. No screw or femoral head displacement relative to baseline (2 days postoperative) was seen in any patient on serial x-rays taken up to 6 months after surgery. This technique adds approximately 10 minutes to surgery time. Advantages of bis-GMA-based composite over traditional PMMA augmentation include mixing on-demand, the ability to make repeated injections over extended periods in the event of femoral head perforations (in one patient in this series), precise placement of adequately small volumes of material, and a lower exotherm. Potentially, this bis-GMA-based composite may reduce the frequency of cut-out complications by enhancing bone-implant interface.

Hydroxyapatite-Coated Screws Prevent Lag Screw Cut-Out in Trochanteric Fractures Fixed with DHS: A Prospective Randomized Study

Hydroxyapatite-Coated Screws Prevent Lag Screw Cut-Out in Trochanteric Fractures Fixed with DHS: A Prospective Randomized Study

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Hip fractures are associated with high morbidity, mortality, and cost. Implants used for hip fracture fixation can fail for many reasons including lag screw cut-out. Tip–apex distance (TAD) is indicative of the position and depth of a screw in the femoral head and has been shown to be associated with cut-out failure. We conducted a systematic review of the published literature to quantify the association between TAD and cut-out failure for patients undergoing hip fracture fixation surgery.We performed a search of the Medline, Embase, and Cochrane databases. We performed abstract and full text reviews independently and in duplicate. We used a random effects model to combine, in duplicate, the incidence of cut-out for patients who had TAD <25 mm and TAD >25 mm. We also combined mean TAD values for patients who had cut-out failure and those who did not.Seventeen studies were eligible for this review, four of which were included in combined analysis of dichotomous outcomes and seven in combined analysis of continuous outcomes. Patients with TAD >25 mm had a significantly greater risk of cut-out than patients with TAD <25 mm (RR = 12.71). Patients who experienced implant cut-out had significantly higher TAD scores than those who did not (mean difference = 6.54 mm).Tip–apex distance is an important concept in relation to cut-out failure of hip fracture fixation surgery. Surgeons should understand and apply the concept of TAD to improve outcomes for their patients.