A clinical and metallurgical analysis of retrieved Jewett and Richards hip plate devices

The metallurgical properties of 61 retrieved 316L stainless steel (ASTM F138-76) hip plate devices used for the treatment of intertrochanteric fractures were examined. Surface and screw-plate interface corrosion characteristics were graded, and grain size, inclusion content, and hardness values were measured. These measurements were then correlated with the clinical performance of the devices. The devices studied included 21 Jewett nail-type and 40 Richards compression screw-type hip plates. The devices had been in situ an average of 26.7 months, with in situ periods ranging from 2.0 to 156.0 months. Cause-related reasons represented the majority of removals (89.8%), while only 10.2% of the hip plates were removed on a routine asymptomatic basis. The data suggest that surgeons consider this type of device as a permanent implant, with removal undertaken only for causative factors. Of all devices removed, 30.6% were retrieved from patients who presented with fracture nonunion. Upon microscopic examination, 97% of the retrieved implants exhibited some degree of either surface of interface corrosion. Statistical analysis revealed significant correlations between corrosion scores and the metallurgical properties of grain size and nonmetallic inclusion content. No statistically significant metallurgical or corrosion differences were discerned between the two types of devices studied. However, four implants of the Jewett design and four of the Richards design were found to be out of ASTM specification F-138-76. It should also be noted that four devices of the Jewett design (19%) fractured in situ, while none of the retrieved Richards designs had fractured. No correlation was observed between the plates' corrosion scores and in situ time.(ABSTRACT TRUNCATED AT 250 WORDS)     

Forearm fracture plates: to remove or not to remove

Eighty dynamic compression plates used to fix fractures of the radius and/or ulna were removed from 51 of 98 adult patients. Thirty-seven patients had plates removed electively. Fourteen patients had plates removed for clinical reasons. The average time from insertion to removal was 13.6 months, with a range from 4.4 to 36 months. Only one refracture occurred through the unhealed both bone forearm fracture site in a patient whose plate was taken out 6 months after surgery. One refracture also occurred through the proximal screw hole of a still implanted ulna plate that had been inserted 3 years earlier. Leaving a plate in for the remaining life of a young patient cannot be considered a benign decision considering the persisting chance for refracture and the potential complications from prolonged exposure to metal corrosion complexes and metal ions.     

Tissue reaction to implant corrosion in 38 internal fixation devices

The corrosion characteristics, metallurgical properties, and clinical performance of 38 retrieved internal fixation devices were correlated with the tissue reaction to these devices. Metallurgical parameters included thin and heavy inclusion content, Rockwell hardness, and grain size. The excised fibrous tissue strip was directly overlying each plate at removal and sectioned between screw-hole sites. The material studied from the 38 plates consisted of 201 screw-hole junctions with associated tissue biopsy sites. Clinical histories were obtained on all 38 patients with hardware removal. The average age at the time of plate insertion was 35.6 years (range, 4 to 75 years). Insertion diagnoses included acute trauma (35 patients), joint dislocations (two patients), and fracture nonunion (one patient). The devices included seven upper extremity bone plates, 19 lower extremity bone plates, and 12 hip screw plates. The devices remained in situ an average of 20.4 months (range, 3 to 60 months). Routine asymptomatic removals were performed on 17 of the patients, while the remaining 21 patients were symptomatic at the time of removal. Included in the reasons for symptomatic removal were pain associated with the implant (eight patients), nonunion (four patients), bursae prominence (three patients), and implant breakage (two patients). Significant correlations were found between average tissue reaction scores and average crevice corrosion scores; a trend of increasing average tissue reaction scores with increasing average screw surface corrosion scores also was observed for the 38 devices, although this relationship was not significant. Average crevice corrosion scores and average screw surface corrosion scores were highly correlated for all removals, and for the asymptomatic and symptomatic removal groups. The metallurgical parameters of thin inclusion content and heavy inclusion content also were significantly correlated for all removals, as well as for symptomatic removals. Similarly, significant correlations were found between the individual tissue reaction scores and crevice corrosion scores from the 201 individual sites, again for all devices and for the asymptomatic and symptomatic removal groups. Tissue reaction scores and time in situ showed significant correlation, with tissue reaction decreasing over time. Crevice corrosion and screw surface corrosion scores were not significantly related to time in situ. The results of this study indicate that there is considerable tissue reaction to the corrosion products of this material.(ABSTRACT TRUNCATED AT 400 WORDS)     

Mechanical and metallurgical properties of carotid artery clamps

The mechanical and metallurgical properties of carotid artery clamps were evaluated. The pressure plate retreat propensity, metallurgical composition, surface morphology, magnetic properties, and corrosion resistance of the Crutchfield, Selverstone, Salibi, and Kindt clamps were tested. None of the clamps showed evidence of pressure plate retreat. The clamps differed significantly in their composition, surface cleanliness, magnetic properties, and corrosion resistance. The Crutchfield clamp was the only one manufactured from an ASTM-ANSI-approved implantable stainless steel (AISI 316) and the only clamp in which the surfaces were clean and free of debris. The Selverstone clamp was made principally from AISI 304 stainless steel, as was one Salibi clamp. The pressure plate on another Salibi clamp was made from a 1% chromium and 1% manganese steel. Machining and surface debris consisting principally of aluminum, silicon, and sulfur was abundant on the Selverstone and Salibi clamps. The Kindt clamp was manufactured from AISI 301 stainless steel with a silicate-aluminized outer coating. The Crutchfield and Selverstone clamps were essentially nonferromagnetic, whereas the Salibi and Kindt clamps were sensitive to magnetic flux. In the pitting potential corrosion test, the Crutchfield clamp demonstrated good corrosion resistance with a pitting potential of 310 mV and no surface corrosion or pitting by scanning electron microscopy examination. The Selverstone clamp had lower pitting potentials and showed various degrees of corrosion and surface pitting by scanning electron microscopy. The Salibi pressure plate had a very low pitting potential of -525 mV and showed severe corrosion. By metallurgical criteria, only the Crutchfield clamp is suitable for long term implantation.     

Retention of forearm plates: risks and benefits in a paediatric population

Most surgeons favour removing forearm plates in children. There is, however, no long-term data regarding the complications of retaining a plate. We present a prospective case series of 82 paediatric patients who underwent plating of their forearm fracture over an eight-year period with a minimum follow-up of two years. The study institution does not routinely remove forearm plates. A total of 116 plates were used: 79 one-third tubular plates and 37?dynamic compression plates (DCP). There were 12 complications: six plates (7.3%) were removed for pain or stiffness and there were six (7.3%) implant-related fractures. Overall, survival of the plates was 85% at 10 years. Cox regression analysis identified radial plates (odds ratio (OR) 4.4, p = 0.03) and DCP fixation (OR 3.2, p = 0.02) to be independent risk factors of an implant-related fracture. In contrast ulnar plates were more likely to cause pain or irritation necessitating removal (OR 5.6, p = 0.04). The complications associated with retaining a plate are different, but do not occur more frequently than the complications following removal of a plate in children.     

Double-stem silicone implant arthroplasty of all metatarsophalangeal joints in patients with rheumatoid arthritis

Double-stem silicone implants have been used to reconstruct destroyed hallux metatarsophalangeal joints (MTPJ) for many years. When smaller implants became available, they were used to reconstruct the lateral four MTPJ. An arthroplasty of all MTPJ was performed using these implants in 44 patients (72 feet) with rheumatoid arthritis (RA). The mean age of patients was 46 years (range, 21 to 66) and 84% were female. Previous surgery had been performed on 28% of the feet. All patients were followed prospectively for an average of 67 months (range, 36 to 111). The patients were evaluated clinically and radiographically; results were recorded on a standardized foot form that allowed computer analysis of the data. The results showed improvement in the hallux valgus angle from 41.6 degrees to 16.1 degrees postoperatively, with no loss of correction over time. Similarly, other forefoot deformities, such as plantar callus and lateral toe abnormalities, all improved both clinically and radiographically. The pain, walking, and function scores all improved, with the greatest improvement being pain relief. Radiographic analysis showed some evidence of fracture in seven hallux (9.7%) and nine lateral toe (3%) implants. Only three toes with implant fracture had some pain at follow-up examination. Three other lateral toe implants were removed for pain. There was no evidence of deep infection or silicone synovitis. Other complications included superficial infection, delayed wound healing, and second surgery for heterotopic bone excision.(ABSTRACT TRUNCATED AT 250 WORDS)     

Lumbar spinal stenosis: results of surgical treatment.

One hundred forty patients with surgically treated lumbar stenosis were evaluated. There were 70 men and 70 women with an average age of 63 years. The average duration of preoperative leg pain and/or claudication symptoms was 16 months. The average follow-up time was 42 months (range, 12-116 months). Average leg pain improvement was 82%, and average back pain improvement was 71%. Thirteen patients (9%) had no leg improvement, 15 (11%) between 25-74% improvement, and 112 (80%), 75% or greater improvement. Ninety-four patients (67%) had 75% or greater back pain improvement, 29 patients (21%) between 25-74% back pain improvement, and 17 patients (12%) no back pain improvement. Factors significantly correlated with poorer outcome included female sex, the presence of compensation or litigation factors, no relief of symptoms from prior surgical procedures, a diagnostic nerve root block preoperatively, and an objective postoperative sensory deficit.     

Arthroscopic subacromial decompression: Results according to the degree of rotator cuff tear

We evaluated the results of arthroscopic subacromial decompression according to the degree of rotator cuff tear in 71 patients, available for follow-up for at least 1 year (average 19 months). Of the patients with stage II disease, 82% were satisfied regardless of whether they had no rotator cuff tear (nine of 11) or had a partial tear (28 of 34) of the rotator cuff. Of patients with stage III disease (complete rotator cuff tear), 88% (23 of 26) were satisfied. An acceptable objective UCLA shoulder rating greater than or equal to 28 points was seen in 82% (nine of 11) of the patients without a rotator cuff tear, 76% (26 of 34) with a partial tear, and 77% (20 of 26) with a complete tear. All four of the patients with complete tears less than 1 cm obtained excellent results. Three of the six failures were in patients with complete tears who had a narrowed acromial-humeral distance of less than 7 mm. The average UCLA pain score showed significant improvement from 2.8 (constant pain) to 8.6 (occasional pain) at 1-2 years postoperatively. The function, strength, and active forward flexion scores also increased at 1-2 years from their preoperative values. The overall patient satisfaction rate of 85% and the objective success rate of 77% are within the range of that seen with open rotator cuff repair.     

Corrosion of aneurysm clips: Evaluation and clinical implications part 1: Metallurgical foundations of stress corrosion failure

Summary Several intracranial failures of aneurysm clips have been documented recently. Consistently, the mechanism of failure has been stress corrosion. These failures could have been anticipated if certain metallurgical properties of the clips had been known. In this paper, we review the metallurgical basis of stress corrosion failure and offer serial metallurgical tests as screening procedures to determine a clip's propensity towards failure. The importance of determining a clip's fracture toughness, a key indicator of stress corrosion resistance, is emphasized.Supported in part through an American Heart Association Student Clerkship in Cerebrovascular Disease Award, 1981. Additional support received from the Bauervic Foundation, Detroit, Michigan, and Medical Materials & Devices, Inc., Pittsburgh, Pennsylvania.     

Erosion of woven polyester pubovaginal sling

PURPOSE: Various materials have been used for pubovaginal slings to correct female stress urinary incontinence. Use of synthetic materials provides a theoretical advantage in that no graft harvesting is necessary. Major risks of synthetic material use are erosion and infection of the sling. We report on erosion of woven polyester slings treated with pressure injected bovine collagen (ProteGen) which required removal. MATERIALS AND METHODS: Office records of patients who had ProteGen slings removed at 5 centers during the last 24 months were retrospectively reviewed. Presenting symptoms, interval between sling placement and removal, subsequent procedures and continence status following sling removal were evaluated. RESULTS: A total of 34 women required removal of the polyester sling secondary to erosion, infection or pain. The most common presenting complaints were delayed vaginal discharge in 21 patients (62%), vaginal pain or pressure in 21 (62%), suprapubic pain in 11 (32%) and recurrent urinary tract infection in 5 (15%) at a mean of 7.95 months (range 1 to 22) after sling placement. Of the patients 17 (50%) had vaginal erosion only, 7 (20%) isolated urethral erosion and 6 (17%) urethrovaginal fistulas. In 4 patients no erosion was obvious but slings were removed secondary to vaginal pain. Before sling removal 16 patients (47%) were totally dry, 13 (38%) had some degree of urinary incontinence and 3 (8%) had retention. Following sling removal 7 patients (20%) remained dry, 25 (74%) had mild to severe stress urinary incontinence with or without urgency and urge incontinence, and 2 (6%) are pending followup. CONCLUSIONS: Woven polyester slings treated with pressure injected bovine collagen are prone to erosion. Although the ProteGen sling was recalled in January 1999, patients who have had the sling placed must be followed closely.     

Is revision surgery following lower-limb amputation a worthwhile procedure? A retrospective review of 71 cases

There is little written about the value of revision surgery on lower-limb amputations. We report on 71 revision amputation procedures performed by a single surgeon in this retrospective analysis. The majority of our revisions (61%) were in amputees who had suffered trauma. We judged success from a surgical and a rehabilitation perspective using scoring systems. Revisions for bony and soft-tissue pathology had good outcomes from a surgical (85% and 82%) and a rehabilitation perspective. Revisions for infection had satisfactory results from a surgical perspective (73%) but less so from a rehabilitation perspective (25%). The results of the revisions for pain were poor showing surgical success only 50% of the time where a neuroma was suspected and only 25% when there was no apparent cause. There was little or no improvement in rehabilitation in both the pain groups.Revision surgery for certain pathologies gives a good surgical outcome and can improve pain and mobility status. Patient selection for surgery is key and evaluation by a multidisciplinary team is recommended.     

Long-term results of resection of the distal ulna for post-traumatic conditions.

Sixty-two patients underwent resection of the distal ulna because of pain or limited motion after wrist trauma. The median length of resection was 23 mm. Injury to the distal radioulnar joint occurred primarily during fractures of the distal radius. Followup time averaged 87 months. The primary surgical indication was pain, but some procedures were performed in an effort to increase motion. All patients improved after surgery. Three patients had residual pain, 25 had mild pain, and 34 had no pain. Supination was greatly improved, with only modest improvement in other wrist motions. Four patients developed ulnar translation of the carpus (from 1 to 3 mm). Pseudoarticulation and ulnar regrowth of the carpus were noted, but neither pseudoarticulation nor regrowth was clinically symptomatic. Grip strength improved significantly after surgery, the average from 45.3 to 78.9% of the unaffected wrist. The presence or absence of radiocarpal arthritis preoperatively had no significant effect on the patients' estimates of results. Overall, 51 patients (82%) had satisfactory results. The primary gains were pain relief, increased supination, and increased strength.     

Indications for implant removal after fracture healing: a review of the literature

Introduction

The aim of this review was to collect and summarize published data on the indications for implant removal after fracture healing, since these are not well defined and guidelines hardly exist.

Methods

A literature search was performed.

Results

Though there are several presumed benefits of implant removal, such as functional improvement and pain relief, the surgical procedure can be very challenging and may lead to complications or even worsening of the complaints. Research has focused on the safety of metal implants (e.g., risk of corrosion, allergy, and carcinogenesis). For these reasons, implants have been removed routinely for decades. Along with the introduction of titanium alloy implants, the need for implant removal became a subject of debate in view of potential (dis)advantages since, in general, implants made of titanium alloys are more difficult to remove. Currently, the main indications for removal from both the upper and lower extremity are mostly ‘relative’ and patient-driven, such as pain, prominent material, or simply the request for removal. True medical indications like infection or intra-articular material are minor reasons.

Conclusion

This review illustrates the great variety of view points in the literature, with large differences in opinions and practices about the indications for implant removal after fracture healing. Since some studies have described asymptomatic patients developing complaints after removal, the general advice nowadays is to remove implants after fracture healing only in symptomatic patients and after a proper informed consent. Well-designed prospective studies on this subject are urgently needed in order to form guidelines based on scientific evidence.     

A prospective evaluation of the PerFix® Plug technique for groin hernia repair

Summary The aim of the study was to prospectively evaluate complication rates, sick-leave, recurrence rate, and chronic post-operative pain after meshplug hernia repair. All 385 consecutive inguinal hernias (373 patients) operated at our department with the PerFix® Plug from September 1996 to December 1997 were included in the study. Follow-up included a questionnaire 3 and 12 months after the repair. Replies to the both of these questionnaires were obtained from 363 of 373 patients (98%). All patients who either reported a lump or sensory disturbance in the operated groin were offered a clinical examination. A third questionnaire focusing on chronic post-operative pain was completed by 77 of 90 patients reporting groin pain. The recurrence rate was 2% (9/385). After 25 months (17–36 months) 38 patients (10%) still experienced inguinal pain to some degree. In 7 male patients there was either pain or discomfort during sexual activities. In a patient with poorly controlled ascites the plug was removed. Day-case surgery was performed in 86% of patients with epidural or local anaesthesia, and 64% in general- or spinal anaesthesia. Employed/self-employed patients were off work for a median of 7 days (0–65). The median time to full recovery for all patients was 20 days. Conclusion: Mesh-plug hernia repair has a reasonably low complication rate together with quick recovery in a non-specialised surgical setting. Chronic inguinal pain is, however, still present to some degree in 10% of patients after two years.     

The management of pain following day-case surgery

The object of this study was to assess patients' experience of pain management following day surgery. One hundred and two patients agreed to take part in a telephone survey, 2 and 4 days following day surgery. The majority of patients (73%) were broadly satisfied with the quality of pain management they received, however, there was room for improvement. Despite modern anaesthesia and surgery, 17% of patients surveyed reported having severe pain immediately following day-case surgery. The majority (82%) of patients left the day-case ward in pain and an even higher proportion (88%) had pain at some time between 2 and 4 days postoperatively. Severe levels of pain following discharge from hospital were a concern for 21% of patients. It was reported that day-case staff did not always ask patients whether they were in pain. Communication with patients is vital in the delivery of optimal care. More support and more information are needed to manage patients' pain effectively, whilst in the day-case wards and also following discharge, at home.     

Fate of rigid fixation in pediatric craniofacial surgery.

The advantages of rigid fixation in adult craniofacial surgery are well documented, and implanted hardware is not routinely removed unless specifically indicated. There is a tendency, however, to remove hardware in children because of concerns with growth restriction, plate migration, and the lack of information on the fate of miniplates when used in pediatric craniofacial surgery. It has been our practice during the past decade not to remove hardware in children unless specifically indicated. Our study included a total of 121 procedures in 96 children, with an average age of 3.9 years and an average follow-up of 5 years. We placed 375 titanium plates and 1944 screws from 3 manufacturers. Complications encountered in children with titanium plates were as follows: 5 cases of delayed growth and 1 instance of restricted growth, 4 screw migrations (none intracranial), 9 palpable plates causing pain, 3 fluid accumulations over plates, 2 cases of meningitis, and 8 instances of plate and screw removal from the above complications. Twenty-two of 96 patients (23%) had a total of 27 complications from 121 procedures (22%). There were 6 cases in which pain precipitated removal of hardware, 1 case of an excessively mobile plate, and 1 case of documented growth restriction requiring removal; therefore our overall reoperation rate for plate removal was 8%, with no intracranial plate or screw migration.     

Incidence of hardware-related pain and its effect on functional outcomes after open reduction and internal fixation of ankle fractures

OBJECTIVES: To document the incidence of late pain and hardware removal after open reduction and internal fixation (ORIF) of ankle fractures. To test the hypothesis that late pain overlying the distal tibial and fibular hardware is associated with poorer functional outcomes. DESIGN: Retrospective review. SETTING: Level II trauma center. PATIENTS: One hundred twenty-six skeletally mature patients undergoing ORIF of unstable malleolar fractures who were followed up for at least six months from injury were included. MAIN OUTCOME MEASUREMENTS: Analog pain score, Short Form-36 Health Survey (SF-36), and Short Form Musculoskeletal Functional Assessment (SMFA). RESULTS: Thirty-nine (31 percent) of the 126 patients had lateral pain overlying their fracture hardware. Twenty-nine patients (23 percent) had had their hardware removed or desired to have it removed. Of the twenty-two patients with hardware-related pain who had undergone hardware removal, only eleven had improvement in their lateral ankle pain; the mean analog pain score decreased from 6 +/- 3.16 (mean +/- standard deviation) before hardware removal to 3 +/- 2.9 after hardware removal (p = 0.008). In general, SF-36 and SMFA scores at final follow-up were significantly lower for patients who had pain overlying their lateral hardware than for those who had no pain. For the group of patients who had lateral ankle pain, no significant difference was noted in SMFA or SF-36 scores for patients who had and who had not had their lateral hardware removed (p > 0.5). CONCLUSION: The incidence of late pain overlying the distal tibial and fibular plate or screws is not insignificant. Although pain is generally decreased after hardware removal, nearly half of patients continue to have pain even after hardware removal. Functional outcome scores are poorer for patients with pain overlying lateral ankle hardware than in those with no pain at this location; this poorer outcome seems to be independent of whether the hardware was removed. Although the results of this study do not support or condemn the routine removal of fracture hardware after healing of unstable ankle fractures, they give orthopaedic surgeons some information that may assist them in counseling patients as to the expected functional outcome after ORIF of ankle fractures and the likelihood of relief of pain after removal of fracture hardware from the distal tibia and fibula.     

Reduction of fretting corrosion of Ti-6Al-4V by various surface treatments

Titanium and titanium-6% aluminum-4% vanadium (Ti-6Al-4V) are known to be biocompatible and corrosion resistant. However, there have been numerous reports of elevated tissue levels of titanium due to passive dissolution, wear, or fretting corrosion of implants. Studies were undertaken to determine whether the fretting corrosion of Ti-6Al-4V could be reduced by surface treatment of one or both surfaces in a fretting situation. Three different surface treatments were studied: ion implantation, physical vapor deposition nitriding, and plasma ion nitriding. The specimens used were screws fretting against the countersinks of a two-hole plate. Fretting corrosion was assessed by weight loss, by chemical analysis of test solutions, and by scanning electron microscopy. Surface treatment of one component, the screws, resulted in reduction in the release of titanium to only 18–32% of that seen with the untreated controls. Weight loss of the untreated plates fretted against physical vapor deposition nitrided screws and plasma ion nitrided screws was reduced to 31 and 38% of the control, respectively. The weight loss of plasma nitrided screws was only 30% that of the control. Nitriding of both plates and screws resulted in a further decrease in plate weight loss and metal release. Plasma ion nitriding of both components had the most significant effect, with the weight loss and titanium release being only 11 and 2% of the control values, respectively.     

Symptomatic plate removal in maxillofacial trauma: a review of 76 cases

This study reviewed the fate of titanium plates used to correct maxillofacial trauma in 76 patients to define risk factors for plate removal. Medical records of 76 consecutive patients at a single institution, over a 10-year period, were retrospectively reviewed. Variables included age, sex, trauma type, diagnosis, fracture type, fracture diagnosis, plate location, surgical approach, and reasons for plate removal. Fracture diagnosis was described as panfacial (42%), blowout (3%), midface (28%), zygoma (26%), mandible angle (6%), ramus (7%), and symphysis (9%). All plate removals according to fracture diagnosis were in the mandible angle (30%) and symphysis (20%). When plate location was reviewed, 68% of the plates were placed in the upper and midface and 32% were placed in the mandible. Specifically, plates were placed in the frontozygomatic suture (18%), zygomaticomaxillary suture (19%), infraorbital rim (14%) and mandible symphysis (15%), mandible angle (9%), piriform (6%), nasal (5%), mandible ramus (4%) and body (4%), zygoma (2%), and frontal (2%). Of 163 plates that were placed, 6 plates (3.7%) were removed. Three (12%) of the symphysis plates and 3 (20%) of the angle plates were removed. Among all variables, only fracture diagnosis (P = 0.01) and plate location (P = 0.01) were statistically significant in plate removal. Five plates were removed for abscess/infection; 1 plate was removed for osteomyelitis. Further review revealed that 4 out of 6 plates removed involved synchronous mandible fractures. Most infections after maxillofacial trauma occur in the mandible, and often these infections are the main reason for plate removal. More vigilance is needed in the treatment of mandible angle and symphyseal fractures, especially if there are synchronous fractures, to prevent infection, plate removal and subsequent malunion.