Absorbable polyglycolide pins in fixation of displaced fractures of the radial head

Summary In a prospective study 24 patients with a displaced fracture of the radial head were treated by open reduction and internal fixation using absorbable polygly-colide pins, 2 mm in diameter. All patients admitted with fractures involving a quarter or more of the radial head, whether comminuted or not, were included in the study whenever there was a displacement of 2 mm or more between the fragments. The mean follow-up time was 28 months (range 15–43 months). A postoperative redisplacement of 1–3 mm between the fragments was seen in four patients with severely comminuted fractures. A transient inflammatory reaction around the implants occurred in two cases 8–12 weeks postoperatively. The functional end-result was classified as excellent or good in 22 patients (91%). This study indicated that successful fixation of displaced fractures of the radial head can be accomplished by using absorbable pins.     

Coronal fractures of the distal femoral condyle: a biomechanical evaluation of four internal fixation constructs

This study evaluated different fixation methods in posterior femoral condyle coronal fractures. A standardised osteotomy was created in synthetic composite femurs and fixed with one of four methods (one 3.5 mm diameter screw, two 3.5 mm screws, one 6.5 mm screw, two 6.5 mm screws). The stiffness and mean loads to specified displacements were measured. The stiffness of two 6.5 mm screws was significantly greater than both single 3.5 mm screw (3567 versus 2584N/mm; p=0.0075) and double 3.5 mm screws (3567 versus 2080N/mm; p=0.003). There was no statistical difference in the stiffness of one 6.5 mm screw compared to either the single or double 3.5mm screws. Increasing the screw diameter and using two screws increased the load at 1, 2 and 3 mm of displacement. In the fixation of posterior femoral condyle fractures, two 6.5 mm screws are more rigid than either single or double 3.5 mm screws. The use of a second screw marginally increases the rigidity of fixation. If 3.5 mm screws are used in the fixation of posterior femoral condyle fractures, at least two screws should be used to approximate the biomechanical stability of a single 6.5 mm screw.     

Biomechanical stability of single-screw versus two-screw fixation of an unstable slipped capital femoral epiphysis model: effect of screw position in the femoral neck

PURPOSE: To biomechanically evaluate single screw and varying 2 screw fixations for an unstable slipped capital femoral epiphysis (SCFE) model using physiologically relevant loading. STUDY DESIGN: In vitro biomechanical study. METHODS: Twenty-four immature porcine proximal femurs were prepared to simulate a mild-to-moderate unstable SCFE. The femurs were randomized into 4 fixation groups: single screw, 2 screws horizontally placed, 2 screws vertically placed, and 2 oblique screws. Biomechanical testing determined maximum load to failure (N), load (N) at 2, 4, 6, and 8 mm of femoral head displacement, and stiffness (newtons per millimeter) for each group. RESULTS: No significant differences were found among the 3 different 2 screw configurations. The 2 screw constructs were 66% stiffer and 66% stronger than the single screw construct. In addition, whereas there was no difference at 2 mm of femoral head displacement, each subsequent displacement (4, 6, and 8 mm) demonstrated significantly higher failure loads when 2 screws were used for stabilization. CONCLUSIONS: Slipped capital femoral epiphysis stabilization with 2 screws leads to increased stability over single screw fixation; however, none of the 3 configurations/placement patterns of the 2 screw constructs seemed to be superior in fixation stability. CLINICAL RELEVANCE: These data support the use of a 2 screw construct in acute/unstable SCFE fixation. The biomechanical benefit of 2 screws needs to be considered in the face of greater potential for inadvertent penetration into the joint with an increased number of screws.     

PLA screw fixation of Lisfranc injuries

Fourteen patients with Lisfranc injuries were treated with open reduction and internal fixation with PLA absorbable screw fixation by a single surgeon. From one to four PLA screws were used in each case (average two). In four patients, K-wires were inserted and removed at six weeks following surgery for instability of the fourth and/or fifth tarsometatarsal joints. Average follow-up was 20 months (range, three to 45 months). No patient was noted to have a soft tissue reaction to the screws. No evidence of osteolysis was noted on any of the follow-up X-rays at the screw sites. No loss of reduction was noted in any follow-up X-rays compared to immediate postoperative radiographs. The use of absorbable screws in this small series was found to be safe, without reaction and obviated the need for screw removal at short-term follow-up.     

Internal fixation of femoral neck fractures with posterior comminution: a biomechanical study

OBJECTIVES: This study was performed to determine whether four cancellous lag screws provide significantly improved rigidity and fixation strength compared with three screws for fixation of displaced femoral neck fractures with posterior comminution. DESIGN: Biomechanical cadaver study. INTERVENTION: Eight pairs of mildly osteopenic femurs were selected, and each pair was fixed with three or four cancellous lag screws (randomly assigned) after the creation of a simulated femoral neck fracture with posterior comminution. A separate comparison with an unmatched group of six similar femurs with a simulated femoral neck fracture without posterior comminution and instrumented with three screws was performed to investigate the effect of posterior comminution. MAIN OUTCOME MEASUREMENT: The specimens were non-destructively tested to determine fixation rigidity in axial and anterior loading. Cyclic axial loading was then performed for 10,000 cycles; the femurs were retested for rigidity and finally were axially loaded until failure. RESULTS: The femurs with a posterior defect stabilized with three screws had significantly less resistance to axial and anterior displacement and sustained significantly lower axial loads to failure than those stabilized with four screws. The specimens instrumented with three screws without a posterior defect exhibited greater resistance to displacement in anterior loading and sustained greater axial loads to failure than those with a posterior defect stabilized with three screws. CONCLUSION: This study suggests that there are benefits to using four screws for fixation of femoral neck fractures with posterior comminution.     

Mini-open approach combined with percutaneous transarticular screw fixation for C1–C2 fusion

This paper describes a limited exposure for posterior C1–C2 arthrodesis aided by percutaneous transarticular fixation. The purpose of this study was to report the fusion rate using the aforementioned method. Fifty-seven patients (54 females and three males) with C1–C2 instability due to rheumatoid disease constituted the material of this study. The exposure was restricted to C0–C3 levels. The drilling and insertion of the screws was done through two mini stab wounds. A special sleeve and screwdriver were developed to facilitate this step. An autogenous iliac bone graft was fixed between the decorticated posterior arch of the atlas and the lamina of the axis vertebra. The mean of the atlantodental interval decreased from 8.5 mm (SD 2.3 mm) to 2.6 mm (SD 0.6 mm) at the immediate postoperative periods and reached 2.7 mm (SD 0.7 mm) after a mean follow-up of 30.4 months (SD 5.6 months). Malposition of the screws was observed in two patients and warranted a second operation in one. Fusion was evident in 98% of the cases. Percutaneous insertion of the screws in posterior C1–C2 transarticular fixation reduces the size of the exposure and the surgical trauma to the cervical segments below the fixation.     

Tissue-implant interface at an absorbable fracture fixation plug made of polylactide in cancellous bone of distal rabbit femur

The tissue-implant interface at a self-reinforced poly-l-lactide (SR-PLLA) expansion plug implanted in distal rabbit femoral cancellous bone was studied histologically, histomorphometrically, and microradiographically in 35 rabbits during consolidation of a transverse transcondylar osteotomy fixed with the SR-PLLA expansion plug. The absorbable plug for internal fixation of fractures and osteotomies measured 4.5 mm in diameter and 30 mm in length and had an expandable distal locking blade system. The femoral specimens were harvested in groups of 5–10 rabbits after a follow-up time of 3, 6, 12, and 24 weeks. The intact controlateral femur served as a control. Vigorous osteogenic response to the implant was already observed at 3 weeks postoperatively, and the osteoid surface fraction at 24 weeks was still significantly higher than in the unoperated contralateral femur. Incomplete union of the osteotomy seemed to result in increased fibrous tissue formation at the tissue-implant boundary. No signs of degradation of the SR-PLLA was observed within the entire follow-up period. The number of inflammatory cells at the tissue-implant interface was low. Consequently, the short-term biocompatibility of the implant was deemed acceptable. Clinical application of the expansion plug is being planned.     

A mechanical evaluation of two fixation methods using cancellous screws for coronal fractures of the lateral condyle of the distal femur (OTA type 33B)

PURPOSE: To compare the relative strength and stability of 2 fixation methods for displaced coronal shear fractures of the lateral femoral condyle (Hoffa fractures, OTA Type 33B3). SETTING: University Biomechanics laboratory. DESIGN: Eight matched pairs of embalmed femurs were divided into 2 groups and simulated Hoffa fractures were created. In each pair, 1 of the fractures was fixed with 2 screws placed in an anteroposterior direction, and in the other, the fracture was fixed with 2 screws placed in a posteroanterior direction. METHODS: All specimens were cyclically tested with simulated physiologic loading. Displacement of the femoral condyle was continuously measured to 10 cycles. The specimens were then loaded to failure. RESULTS: Fixation with posterior to anteriorly placed cancellous lag screws was significantly more stable than that with anterior to posteriorly placed screws at 10 cycles (P = 0.05), with 0.67 mm displacement compared to 1.36 mm, respectively. They were also more stable at 10, 100, and 1000 cycles; however, these displacements were not statistically significant. Fixation with posteriorly placed cancellous screws also had significantly higher ultimate strength (P = 0.04), 1700 N compared to 1025 N for anterior placement. CONCLUSION AND SIGNIFICANCE: Lag screws placed posterior to anterior provided more stable fixation of Hoffa fractures in embalmed femurs than anteroposteriorly placed lag screws. This finding may apply in the clinical setting; however, this technique requires that the screw heads be recessed beneath the articular surface. The effects of the cartilage defects so created are not known. The choice of technique is also determined by concomitant fractures and the exposure required for their fixation.     

可吸收钉内固定治疗股骨头骨折并髋关节后脱位的临床体会

目的 总结可吸收钉内固定治疗股骨头骨折并髋关节后脱位的临床体会. 方法 采用可吸收钉内固定治疗股骨头骨折并髋关节后脱位患者7例.股骨头骨折按照Pipkin's骨折分型:Ⅰ型2例,Ⅱ型3例,Ⅲ型1例,Ⅳ型1例.股骨头骨折块最小2.0 cm×2.0 cm×2.5 cm,最大4.5 cm×3.5 cm×4.0 cm.受伤至就诊时间为1 h～12d.Ⅰ型2例和Ⅱ型3例经Smith-Peterson入路,Ⅲ型1例和Ⅳ型1例采用Kocher-Langenbeck入路,以直径4.5 mm,长度35～55mm的可吸收螺钉内固定股骨头骨折块.结果 本组7例均获随访,平均时间31.7(14 ～57)个月.按Thompson-Epstein临床和影像学评定标准评定疗效,优3例,良2例,可1例,差1例,优良率71.4％.1例Ⅳ型股骨头骨折患者,术后出现股骨颈骨折不愈合,1年后出现股骨头坏死,伤后2.5年行人工全髋置换术,其余均完全愈合. 结论 可吸收钉治疗股骨头骨折并髋关节后脱位具有无需二次手术、取材方便等优点,值得临床推广应用.     

The Artek cup for total hip replacement of dysplastic hip joints

Background One specific difficulty in total hip replacement for developmental dysplasia of the hip is a shallow acetabulum with a short anteroposterior diameter. In a prospective cohort study we investigated the short-term results of the Artek cup, designed with a shallow outline and a height-reduced metal inlay for a large size 38 mm metal head, in a group of female patients with mild dysplasia of the hip.Methods Fourteen consecutive patients with 17 dysplastic hip joints were included in the study. Their average age was 42 years. Fourteen hips had dysplasia Crowe grade I; 3 hips had dysplasia Crowe grade II. The femoral head centre was localized according to Pagnano in zone 1 in 3 cases, in zone 3 in 6 cases, and in zone 4 in 8 cases. The Harris hip score was 49 points (range 30–68 points).Results Mean follow-up was 20 months (range 14–24 months). The Harris hip score improved to a mean of 91 points (range 78–98 points). The postoperative radiographic measurements showed an inclination angle of 52.1° (range 43–66°). The femoral head centre was in Pagnano zone 1 in 13 cases, in zone 2 in 1 case, in zone 3 in 1 case, and in zone 4 in 2 cases. The mean postoperative deviation from the approximative rotational centre was 0.17 mm (range -15 to 13 cm) in the superior direction and 5.3 mm (range -5 to 17 mm) in the lateral direction.Conclusion In a small series of 17 implantations, stable press-fit fixation without screws or bone grafting was achieved despite acetabular defects. The complication rates were high. Inclination angles up to 54° were not correlated with complications. Inclination angles of 60° and more led to subtotal or complete dislocation. Mid-term results are still to follow concerning wear, dislocation rate, loosening and revision.An erratum to this article can be found at     

关节镜下可吸收螺钉与金属螺钉重建ACL术后比较

目的膝关节镜下采用可吸收界面螺钉与金属界面螺钉重建膝关节前交叉韧带术后结果比较。方法选择随访1年以上采用可吸收界面螺钉和金属界面螺钉,自体骨-髌腱-骨移植肌腱重建膝前交叉韧带105例,分为3个组:股骨及胫骨隧道均采用可吸收界面螺钉固定60例为组;股骨隧道采用可吸收界面螺钉而胫骨用金属界面螺钉固定25例为组;股骨及胫骨隧道均采用金属界面螺钉固定20例为组。术前术后物理检查,包括:抽屉试验、Lach-man试验、Pivot shift试验,此外放射线拍片、KT-2000测定,最后Lysholm膝关节评分。结果术前Lysholm膝关节评分平均值:组58.8分,组56.1分,组56.9分,术后恢复为组89.6分,组91.6分,组89.7分。术前KT-2000测定平均值:组6.89 mm,组6.88 mm,组7.15 mm,术后恢复为组2.95 mm,组2.86 mm,组3.04 mm。术后6周至3个月间复查,只有组出现膝关节轻度弛缓症状,但以后逐渐恢复,与另外两组比较未见统计学差异。结论采用两种界面螺钉不管在关节稳定性还是术后并发症上均没有统计学差异。只是术后3个月内均采用可吸收界面螺钉组有轻度弛缓症状,故作者提倡股骨用可吸收界面螺钉、胫骨用金属界面螺钉,而且术后3个月内有必要采取支具等辅助措施进行功能康复。     

骨软骨原位覆盖可吸收螺钉治疗股骨头骨折

目的总结骨软骨原位覆盖可吸收螺钉治疗股骨头骨折的效果。方法 28例股骨头骨折,按Pipkin分型：Ⅰ型8例,Ⅱ型13例,Ⅲ型1例,Ⅳ型6例。均采用骨软骨原位覆盖可吸收螺钉固定股骨头骨折;Ⅲ型骨折采用股骨近端支撑钢板固定股骨颈骨折;Ⅳ型骨折髋臼骨折片较小可去除,骨折片较大时可采用可吸收螺钉或重建钢板固定。结果所有患者术后无伤口感染发生,均伤愈出院。术后随访25例,平均随访25（2～63）个月,疗效评价：优16例,良5例,可3例,差1例。结论应用骨软骨原位覆盖可吸收螺钉治疗股骨头骨折突破了可吸收材料禁用于关节内骨折的禁忌,是一种实用、有效的方法。     

Comparison of costs in ankle fractures treated with absorbable or metallic fixation devices

The economic costs of ankle fractures treated operatively with self-reinforced polyglycolide acid (SR-PGA) screws, with self-reinforced poly-L-lactide acid (SR-PLLA) screws or with metallic implants was determined. All patients were divided into three groups according to the fixation material used. Open and otherwise complicated fractures were excluded. The total expense of operations in each group was taken into account. The average total cost of an ankle fracture fixed with SR-PGA screws was £3503. In the SR-PLLA group it was £3906, and in the metallic group it was £4514. Total expenses were £1011 higher in the metallic group than in the SR-PGA group, and consequently, expenses in the metallic group were £608 higher than in the SR-PLLA group. According to this study, it seems that absorbable fixation devices are more economical than metallic implants in operative treatment of ankle fractures though as part of the differences in total expense in this series is due to the age of the patients and other dissimilarities between these groups, the results have to be interpreted carefully.     

Immobilisierung und Frühmobilisierung von Malleolarfrakturen nach Osteosynthese mit resorbierbaren Schrauben

71 patients with displaced ankle fracture were treated by using absorbable screws in the fixation of fractures. The follow-up time was 17 (13 to 33) months in average. The fixation devices were SR-PLLA (self-reinforced poly-L-lactide) and SR-PGA (self-reinforced polyglycolide) screws. 38 of the ankle fractures were immobilized with plaster cast and 33 ankle joints were mobilized immediately with a brace. An exact radiological result was achieved in 66 cases, insignificant displacement was observed in four cases and the result was poor in one patient. The result was classified as excellent in 62 patients, as good in eight patients and as poor in one patient. The patients treated postoperatively without plaster healed in a somewhat shorter time, but at one year check-up the differences in the clinical results were almost eliminated. Selected ankle fractures fixed with absorbable screws can be treated postoperatively with early mobilization without plaster.     

Antegrade nailing of femoral shaft fractures combined with neck or distal femur fractures

Introduction Complex femoral fractures pose considerable therapeutic challenges to orthopedic surgeons. We present a retrospective review of 25 patients with complex femoral fractures treated with intramedullary locked nailing and supplemental screw fixation.Materials and methods Fifteen patients with ipsilateral femoral neck and shaft fractures (group 1) and 10 patients with ipsilateral femoral shaft and distal femur fractures (group 2) were treated from 1990 to 1998. High-energy injuries occurred in all patients. There were 4 open fractures. Antegrade, locked nailing of diaphyseal fractures was performed in all cases. Supplemental screws for the neck were used in all patients in group 1 and in 3 patients in group 2.Results All of the fractures united during the follow-up. Five patients in group 1 underwent reoperation (33.3%): one due to a delayed union, the second due to an implant failure, the third due to a nonunion of a neck fracture, and the last two because of an initially missed femoral neck fracture. None of the patients in group 2 underwent reoperation. Angular malalignment of the shaft was found in 6 fractures in group 1 (average 4.8^o, range 3^o–11^o) and in 4 fractures in group 2 (average 6^o, range 3^o–12^o). Shortening of the limb occurred in 3 patients in group 1 (average 1.4 cm, range 1–1.8) and in 1 patient in group 2 (2 cm). Loss of fixation was seen in 1 patient in each group. Avascular necrosis and infection were not seen in any case in both groups.Conclusion Femoral intramedullary nails with antegrade or retrograde options for insertion and different locking possibilities have extended the indications to include both diaphyseal and metaphyseal fractures. New nail designs, usually more expensive than the conventional nails, have been introduced into the market for this purpose. One has to keep in mind that antegrade, locked nailing of femoral shaft fractures combined with neck or distal femur fractures is a technically demanding but efficacious procedure. The success rate is high when the technique is meticulously implemented.     

Intramedullary fixation of pertrochanteric hip fractures with the short AO-ASIF proximal femoral nail

Introduction The advantages of intramedullary fixation of pertrochanteric hip fractures over dynamic screw-plate devices in the clinical setting are still a matter of debate. We performed a case series study in a teaching hospital to analyse the results of the recent AO-ASIF proximal femoral nail (PFN).Materials and methods Between July 1998 and May 2001, 46 consecutive patients (47 fractures) were included in the investigation. The average patient age was 76.4 years (range 50–93 years), and most fractures (74.5%) were unstable. Operative details, adequacy of fracture reduction, screw position in the femoral head, re-operations, and postoperative complications were documented. Functional results were evaluated by the Parker and Palmer mobility score and Barthel Index for patients with a minimum follow-up of 4 months.Results Intraoperative technical or mechanical complications occurred in 11 patients (23.4%), mostly problems with the distal nail locking and fracture of the lateral wall of the greater trochanter. Mean surgical time was 83.4 min. The lateral protrusion of screws causing thigh pain was the most common postoperative complication, with an incidence of 21.2%. There was only one femoral shaft fracture at the nail tip caused by a fall at 9 months of follow-up. Five patients (10.6%) had intra-articular migration of screws, which was associated with loss of reduction and varus collapse in one case. There were 2 persistent deep infections and 2 haematomas that required surgical drainage. The re-operation rate was 19.1%, mainly cephalic screw removal due to lateral protrusion at the proximal thigh. Ten patients (32.2%) fully recovered their Parker and Palmer mobility score, and 20 patients (66.6%) recovered more than 90% of their pre-injury Barthel Index values. The average limb shortening was 14 mm. Mortality rate during the observation period was 20.4%.Conclusion In view of only one loss of reduction with varus collapse clearly caused by a technical error, we concluded that the PFN is a suitable implant for unstable fractures, but the high re-operation rate precludes its routine use for every pertrochanteric fracture.     

Broches et vis biorésorbables: une nouvelle méthode de fixation des fractures de l'olécrâne

Résumé Quarante et un malades présentant une fracture de l'olécrâne ont été traités au moyen de broches et vis biorésorbables. Onze fractures étaient comminutives. Les broches ont été utilisées chez 20 malades (groupe 1) et les vis chez 21 malades (groupe 2). Les résultats radiologiques ont été bons dans 34 cas (83%), moyens dans 5 cas (léger déplacement de la fracture ou légère incongruence articulaire), et mauvais dans 2 cas nécessitant une ré-intervention (ostéosynthèse défaillante dans un cas et fragment déplacé dans un autre cas). Il y a eu 4 retards de consolidation. A un an, les résultats fonctionnels ont été au moins satisfaisants dans 39 cas (95%), Il n'y a pas eu de différence significative dans les résultats entre les deux groupes. Cette étude montre que les broches et les vis biorésorbables sont un matériau fiable dans la fixation des fractures de l'olécrâne. Leur avantage par rapport aux matériaux métalliques conventionnels est qu'ils évitent la réintervention pour retirer le matériel d'ostéosynthèse.

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Absorbable rods and screws: a new method of fixation for fractures of the olecranon

Summary Between April 1986 and July 1990 fractures of the olecranon in 41 adult patients were treated by fixation with absorbable rods (20 patients) and screws (21 patients) of self-reinforced polyglycolide (SR-PGA), 3.2 mm in diameter and 20–70 mm in length. Patients were followed up for a mean time of 2 years 7 months (range 1 year to 4 years 6 months). After reduction of the fracture, channels were drilled from the proximal fragment through the cortex of the distal fragment and the fractures were fixed with absorbable rods or screws. By one year from follow-up maintenance of an anatomical reduction of the fracture was seen in 34 patients. Failure of fixation requiring a second operation occured in 2 cases. In all cases functional recovery was at least satisfactory. Sinus formation as a sign of transient tissue reaction was observed in 3 cases, but did not influence the healing of the fractures or the functional recovery. The results in patients treated with rods or screws was similar. Absorbable screws combined with small rods and absorbable sutures allow treatment of +ore severe fractures of the olecranon than do rods alone.

     

可吸收高强度左旋聚丙交酯螺钉内固定兔股骨髁截骨

目的 应用新式可吸收材料的增强技术-固态压缩法制得高强度可吸收左旋聚丙交酯(SC-PLLA)螺钉。通过观察其固定动物股骨髁截骨后骨折愈合和组织反应，评估该装置的固定效能和生物相容性。方法 12只新西兰免于右侧股骨髁横向截骨，单枚SC-PLLA螺钉固定。术后4、8、12、36周处死，行放射学和组织学检查。结果 所有截骨周围均能明显地观察到骨痂，未见明显畸形。镜下见截骨愈合为骨性连接，骨组织可与PLLA直接接触。结论 SC-PLLA对承重松质骨的固定可靠，并且牛物相容性良好。     

Posterior fixation of subaxial cervical spine fractures in patients with ankylosing spondylitis

Cervical spine fractures in patients with ankylosing spondylitis are serious and potentially lethal injuries with high complication rates. Treatment obstacles include long lever arms that generate large forces on any fixation device, osteoporosis, and, usually, kyphotic deformity. The Olerud Cervical Fixation System (OC), with cervical pedicle screws and rods, offers an opportunity to create a biomechanically stable posterior fixation in these complicated cases. The present study is a retrospective chart review and a radiological follow-up of patients with this diagnosis, treated at our department between 1995 and 2000. Nineteen patients (two women) with a mean age of 60 years (32–78 years) were included. The fracture levels were predominantly C5–C6 (five patients) and C6–C7 (five patients). All patients were treated with a long posterior fixation with the OC, and in four patients this was combined with an anterior plate fixation. One patient with severe lordosis also received a short posterior plate fixation. The patients notes and plain radiographs have been reviewed. Five patients died during the post-operative follow-up period; the others had a mean follow-up time of 24 months (10–55 months). Eleven patients had no neurological deficits preoperatively. One of them developed moderate weakness in his right arm, postoperatively, due to a misplaced pedicle screw in the right pedicle of C5. However, after extraction of the screw he almost totally recovered in 6 months. Eight patients had neurological deficits. Two were paraplegic; two had motor weakness combined with sensory deficiency, and four had a sensory deficiency. Two of the patients with neurological deficits improved postoperatively, but the others were unchanged. Peroperative problems were recorded in five patients; one C6 pedicle was perforated, and two patients had pedicles on one or more levels that the surgeon was not able to probe. In one of the latter patients, transfacet screws were chosen, instead, for one of the levels. Extensive peroperative bleeding was encountered in two patients. One deep-wound infection was noted, postoperatively, and required surgical drainage, but no patients have been re-operated due to loosening of the instrument or to healing problems. In conclusion, the results of the present study indicate that the OC—and possibly other similar long-fixation systems that allow using both pedicle screws and lateral mass screws rigidly connected to a rod—is suited for treating subaxial cervical spine fractures in patients with ankylosing spondylitis, allowing high healing rates.     

A Simple Modified Technique for In-Situ Screw Fixation in Slipped Capital Femoral Epiphysis

BackgroundIn-situ pinning has a definite role in the management of slipped capital femoral epiphysis (SCFE). We describe a modified technique for in-situ screw fixation on a regular radiolucent operating table which avoids certain complications innate with the existing techniques.MaterialsSixty consecutive hips which underwent either in-situ fixation for SCFE (28 hips) or prophylactic fixation of the contralateral hip (32 hips) by the modified technique were analysed. The femoral head was divided into three zones (A-central, B-middle, C-peripheral) of equal circles. The zone of the screw was noted in both AP and lateral views. The angle between the physeal line and the screw in AP(S_AP) and lateral (S_lat) view, and the distance from screw tip to articular surface in both views were measured.ResultsIn AP view, 55/60 (91.6%) screws were in zone-A, and five were in zone-B. In the lateral view, 56/60 (93.3%) screws were in zone-A, and four were in zone-B. There was no screw placed in zone-C in either of the views. The average deviation was < 15° in AP view and < 7° in lateral view from the ideal placement. The mean distance from the screw tip to the articular margin in AP was 5.15 mm and that in lateral was 6.15 mm. The interobserver agreement rate was found to be 0.8. No patient had intraoperative breakage of a drill bit or joint penetration, avascular necrosis, chondrolysis or screw-related complications at a minimum follow-up of one year.ConclusionIn-situ pinning on the radiolucent table is safe and has distinct advantages. The modified technique of in-situ screw fixation adds to the safety and accuracy of the procedure.Level of EvidenceLevel IV.