Mid-term Results of Revision Total Hip Arthroplasty Using Delta Ceramic-on-Ceramic Bearing

Background@#Delta ceramic-on-ceramic (CoC) articulation affords excellent outcomes in primary total hip arthroplasty (THA). However, the safety and reliability of this bearing in revision THA need more evidence. This study aimed to report complications, radiological changes, clinical results, and survivorship of revision THA using Delta CoC articulation at minimum 5-year follow-up. @*Methods@#We reviewed 118 revision THAs (113 patients: 68 men and 45 women) performed with use of Delta CoC bearing. Their mean age was 58.7 years (range, 30–90 years) and their mean body mass index was 24.6 kg/m 2 (range, 15.2–32.5 kg/m 2 ). These patients were followed up for 5–12 years (mean, 7.2 years). We evaluated squeak, grinding sensation, ceramic fracture, dislocation, periprosthetic joint infection (PJI), periprosthetic fracture, prosthetic loosening, ceramic wear, osteolysis, modified Harris hip score (mHHS), and survivorship with any reoperation after the revision as the endpoint. @*Results@#Two patients (1.7%) had grinding sensation, but no patient had ceramic fracture. Reoperations were necessary in 9 hips (7.6%) due to PJIs in 2, stem loosening in 2, cup loosening in 2, recurrent dislocation in 2, and periprosthetic fracture in 1. No hip had measurable wear or osteolysis. The average mHHS improved from 53.3 points before the revision to 82.3 points at the final follow-up. Survivorship was 91.6% (95% confidence interval, 86.3%–96.9%) at 12 years. @*Conclusions@#The Delta ceramic bearing appeared a reliable option for revision THA, showing encouraging mid-term results with acceptable survivorship and a low complication rate.

Posterior Surgery with Selective Anterior Reinforcement and Screw Augmentation for a Delayed Myelopathy from an Osteoporotic Vertebral Compression Fracture / 대한정형외과학회잡지

Purpose@#In delayed myelopathy (DM) from osteoporotic vertebral compression fractures (OVCF), the mechanisms of spinal cord impingement differ according to the stability of the fractured vertebra. This study examined the availability of a posterior surgery comprised of pedicle screw augmentation with polymethylmethacrylate (PMMA) and selective anterior reinforcement (PS-PMMA+SAR) according to the stability. @*Materials and Methods@#This was a retrospective single-center study. The consecutive patients who had a PS-PMMA+SAR for a DM from OVCF and were followed up more than two years were reviewed. Thirty patients were eligible for this study. All patients used fenestrated screws for PMMA augmentation. Anterior reinforcement was selected according to the stability. The unstable type was done by filling the vacuum cleft with bone chips or PMMA, and the stable type was done by vertebral body anterior translation with/without an interbody bone graft. The radiological and functional outcomes were evaluated. @*Results@#There were 20 unstable and 10 stable cases. The regional kyphotic angle was improved significantly from 31.3°±10.8° to 10.4°±8.3° (p<0.001). The anterior vertebral height ratio was improved significantly from 39.4%±17.1% to 86.4%±9.2% (p<0.001). The spinal canal invasion ratio was improved significantly from 39.2%±14.8% to 19.1%±10.8% (p<0.001). The walking ability was improved mostly by two Nurick’s grades (p<0.001). The Oswestry disability index was improved from 72% to 33% (p<0.001). @*Conclusion@#Posterior surgery with PMMA-augmented pedicle screws, and selective anterior reinforcement for DM from OVCF was available to achieve a good functional and radiological outcome.

Hip Fracture Management during the COVID-19 Pandemic in South Korea

Background@#The purpose of this study was to introduce a screening system for coronavirus disease 2019 (COVID-19), to evaluate the overall orthopedic management in hip fracture patients during the COVID-19 pandemic in South Korea, and to compare the surgical results in hip fracture patients during the COVID-19 pandemic with those of the previous year. @*Methods@#Hip fracture patients who visited emergency rooms were screened at the screening clinics before admission. The medical management was carried out with the medical staff wearing surgical masks, meticulous hand hygiene observed, and a minimum distance of 2 m between patients maintained. The demographics, operative parameters, and surgical results of patients treated during the pandemic were compared with those from the previous year. @*Results@#From January 2020 to July 21, 2020, 119 patients with hip fractures (33 men and 86 women) were admitted to our institution for surgical treatment. Five patients showed symptoms of pneumonia, but no patient was positive for COVID-19. The mortality rate during the study period was 4.2%, and none of the patients died due to COVID-19. The interval between admission and surgery and the length of hospital stay were significantly shorter (p = 0.008, p = 0.002) and the proportion of spinal anesthesia was greater in hip fracture patients during the COVID-19 pandemic compared to those from the previous year (p = 0.011). @*Conclusions@#The COVID-19 screening system for hip fracture patients has proven to be effective in preventing intrahospital spread of the disease. Hip fracture surgery performed during the COVID-19 pandemic has shown comparable results without any COVID-19 infection and COVID-19-related mortality.

The Influence of Femoral Internal Rotation on Patellar Tracking in Total Knee Arthroplasty Using Gap Technique

Background@#Femoral internal rotation in total knee arthroplasty (TKA) is well known as one of the main causes of patellar maltracking. Although femoral internal rotation in TKA is considered unacceptable due to the risk of patellar maltracking, it is sometimes required for ligament balancing. We evaluated the influence of femoral internal rotation on patellar tracking in TKA performed using the gap technique. @*Methods@#From April 2008 to May 2018, 1,612 cases of TKA were done. Among them, 245 cases of TKA for osteoarthritis were followed up for at least 1 year and included in this study. We compared patellar tracking in two groups; group I consisted of 99 cases whose femoral rotation was less than 0° and group II consisted of 146 cases whose femoral rotation was 3°–5° external rotation. Preoperative femoral rotation was measured with the condylar twist angle (CTA) by using computed tomography. The patella was replaced in all cases. Patellar tracking was evaluated with patellar tilt angle (lateral tilt [+] and medial tilt [–]) in the merchant radiograph. Statistical analysis was done using Mann-Whitney U-test. Clinical assessment was performed using the Knee Society clinical rating system. @*Results@#The preoperative CTA was 5.3° ± 1.6° in group I and 5.4° ± 1.6° in group II, showing no statistically significant difference between groups (p = 0.455). Intraoperative femoral rotation was –0.5° ± 0.8° in group I and 3.9° ± 0.8° in group II when the gap technique was used (p < 0.001). The postoperative patellar tilt angle was –0.4° ± 3.6° in group I and 0.1° ± 4.1° in group II with no statistically significant difference (p = 0.251). @*Conclusions@#Compared with femoral external rotation, femoral internal rotation with ligament balance in TKA was not more associated with patellar maltracking. Therefore, patellar tracking might be related with ligament balance in flexion regardless of the anatomic femoral rotational alignment.

The Influence of Femoral Internal Rotation on Patellar Tracking in Total Knee Arthroplasty Using Gap Technique

Background@#Femoral internal rotation in total knee arthroplasty (TKA) is well known as one of the main causes of patellar maltracking. Although femoral internal rotation in TKA is considered unacceptable due to the risk of patellar maltracking, it is sometimes required for ligament balancing. We evaluated the influence of femoral internal rotation on patellar tracking in TKA performed using the gap technique. @*Methods@#From April 2008 to May 2018, 1,612 cases of TKA were done. Among them, 245 cases of TKA for osteoarthritis were followed up for at least 1 year and included in this study. We compared patellar tracking in two groups; group I consisted of 99 cases whose femoral rotation was less than 0° and group II consisted of 146 cases whose femoral rotation was 3°–5° external rotation. Preoperative femoral rotation was measured with the condylar twist angle (CTA) by using computed tomography. The patella was replaced in all cases. Patellar tracking was evaluated with patellar tilt angle (lateral tilt [+] and medial tilt [–]) in the merchant radiograph. Statistical analysis was done using Mann-Whitney U-test. Clinical assessment was performed using the Knee Society clinical rating system. @*Results@#The preoperative CTA was 5.3° ± 1.6° in group I and 5.4° ± 1.6° in group II, showing no statistically significant difference between groups (p = 0.455). Intraoperative femoral rotation was –0.5° ± 0.8° in group I and 3.9° ± 0.8° in group II when the gap technique was used (p < 0.001). The postoperative patellar tilt angle was –0.4° ± 3.6° in group I and 0.1° ± 4.1° in group II with no statistically significant difference (p = 0.251). @*Conclusions@#Compared with femoral external rotation, femoral internal rotation with ligament balance in TKA was not more associated with patellar maltracking. Therefore, patellar tracking might be related with ligament balance in flexion regardless of the anatomic femoral rotational alignment.

Clinical Results of Medial Unicompartmental Knee Arthroplasty in Elderly Patients Older than 70 Years of Age / 대한정형외과학회잡지

Purpose@#To evaluate the long-term clinical results and survivorship of unicompartmental knee arthroplasty (UKA) in elderly patients older than 70 years by analyzing cases that have been implanted for >10 years ago. @*Materials and Methods@#The long-term follow-up results were evaluated in 39 patients (46 cases) who underwent medial UKA from March 2002 to February 2004. The mean age of the patients at the time of surgery was 74.0 years, and the preoperative diagnosis was degenerative arthritis of the knee in all cases. @*Results@#Of the 46 cases, reoperation occurred due to the complications in four cases. In 22 cases without 14 cases of death and six cases of follow-up loss, follow-up more than 10 years was possible. The mean Knee Society knee and function scores improved significantly from 53.0 and 52.5 points pre-operatively to 89.4 and 80.9 points at the last follow-up, respectively (p<0.001). The mean range of motion of the knee recovered to 132.5°, and the mean tibiofemoral angle changed to 5.9° of valgus at the last follow-up. Complications following the UKA occurred in four cases; the most prevalent complication was mobile bearing dislocation (n=2). One case of failure occurred due to aseptic loosening and degenerative arthritis of the lateral compartment, respectively. The cumulative survival rate of the implants was 95.0% at 10 years and 85.7% at 15 years. Of the 40 cases, excluding six cases of follow-up loss, 36 cases (90.0%) could be used without reoperation until death or at the last follow-up after surgery. @*Conclusion@#These results showed the outstanding functions of the knee and satisfactory long-term survivorship after UKA. Therefore, UKA could be a useful method for the treatment of osteoarthritis of the knee in elderly patients older than 70 years of age.

Effects of Nursing Professionalism and Job Stress on the Problem Solving Ability of Community Health Practitioners / 간호행정학회지

Purpose@#The purpose of this study was to examine the influences of nursing professionalism and job stress on problem solving ability of community health practitioners. @*Methods@#The participants were 167 community health practitioners. Data were collected from December 18 to 28, 2019. Self-report questionnaires were administered to collect data regarding general characteristics, degree of nursing professionalism, job stress, and problem solving ability. Data were analyzed using descriptive statistics, independent t-test, One-way ANOVA, Pearson correlation coefficients and multiple regression analysis. @*Results@#The factors influencing the degree of problem solving ability of the community health practitioners were professionalism of nursing (β=.29, p<.001), and interpersonal factors (β=-.25, p=.001). It was found that 15% could explain problem solving ability. @*Conclusion@#It is necessary to strengthen the professionalism of nursing and to decrease the interpersonal factors due to job stress for the community health practitioners. The results indicate a need to increase development of educational programs for capacity building of community health practitioners.

Clinical Effects and Complications of Pedicle Screw Augmentation with Bone Cement: Comparison of Fenestrated Screw Augmentation and Vertebroplasty Augmentation

Background@#Pedicle screw augmentation with bone cement has been experimentally demonstrated to increase the pullout strength. However, the mechanisms of screw loosening are complicated and interacting. Although vertebroplasty augmentation and fenestrated screw augmentation have been compared in many studies, there has been no comparative study on their clinical effects and complications in real clinical settings. We investigated clinical effects of bone cement augmentation of a pedicle screw and differences according to augmentation methods. @*Methods@#Of the total 241 patients who had osteoporosis and underwent posterior pedicle screw fixation without anterior bone graft between January 2010 and December 2016, 132 patients with ≥2 years of radiological follow-up were included in this retrospective study. The patients were divided into group I (unaugmented) and group II (bone cement augmented). Group II was subdivided into II-S group (solid screw augmented) and II-F group (fenestrated screw augmented). The incidence of screw loosening was compared between groups I and II. Cement leakage, screw loosening, and screw fractures were investigated in the subgroups. @*Results@#In total, 36 of 71 (52%, group I) unaugmented cases and 96 of 170 (56%, group II) augmented cases were followed up for ≥2 years. Of the total 78 solid screw augmented cases, 42 (56%) were in II-S group; 54 of the total 92 (59%) fenestrated screw augmented cases were in II-F group. Groups I and II were homogenous regarding demographic characteristics; II-S and II-F groups were also homogenous. The incidence of screw loosening was 50.0% (18/36) in group I and 7.3% (7/96) in group II (p < 0.001). Cement leakage developed in 2 of 42 (4.8%) cases in II-S group and in 5 of 54 (9.3%) cases in II-F group (p = 0.462). Screw loosening developed in 6 of 42 (14.3%) cases in II-S group and in 1 of 54 cases (1.9%) in II-F group (p = 0.041). Screw fracture developed in none of 42 cases in II-S group and in 3 of 54 cases (5.6%) in II-F group (p = 0.254). @*Conclusions@#In osteoporotic patients, bone cement augmentation of a pedicle screw decreased the incidence of screw loosening, and fenestrated screw augmentation was more effective than vertebroplasty augmentation.

Can We Prevent a Postoperative Spinal Epidural Hematoma by Using Larger Diameter Suction Drains?

BACKGROUND: Epidural hematoma is a rare but serious complication. According to previous studies, it is not prevented by suction drains. This study evaluated the following alternative hypothesis: the larger the diameter of a suction drain, the less the remaining epidural hematoma after spinal surgery. METHODS: This was a randomized prospective study. Patients who underwent posterior lumbar decompression and instrumented fusion were divided into two groups: the large drain (LD, 2.8-mm-diameter tube) and small drain (SD, 1.6-mm-diameter tube) groups according to the diameter of the suction drains. All patients were consecutive and allocated alternately according to the date of operations. Suction drains were removed on day 3 and magnetic resonance imaging was performed on day 7 postoperatively. The size of remaining hematomas was measured by the degree of thecal sac compression in cross section using the following 4-point numeric scale: G1, less than one quarter; G2, between one quarter and half; G3, more than half; and G4, more than subtotal obstruction. RESULTS: There were 39 patients with LDs and 38 with SDs. They did not differ significantly in terms of sex, number of fusion segments, revision or not, antiplatelet medication, intraoperative injection of tranexamic acid. However, patient age differed significantly between the two groups (LD, 63.3 years and < SD, 68.6 years; p = 0.007). The two groups did not differ significantly in terms of prothrombin time, activated partial thromboplastin time, platelet number, blood loss, or operation duration. However, platelet function analysis exhibited a significant difference (LD, 164.7 seconds and < SD, 222.3 seconds; p = 0.002). The two blinded readers showed high consistency (Kappa value = 0.740; p = 0.000). The results of reader 1 were as follows: LD and SD had 21 and 21 cases of G1, 9 and 11 cases of G2, 6 and 6 cases of G3, and 3 and 0 cases of G4, respectively. The results of reader 2 were as follows: LD and SD had 22 and 23 cases of G1, 7 and 9 cases of G2, 7 and 6 cases of G3, and 3 and 0 cases of G4, respectively. There was no difference between the two groups (reader 1, p = 0.636; reader 2, p = 0.466). CONCLUSIONS: The alternative hypothesis was rejected. Therefore, postoperative spinal epidural hematoma would not be prevented by LD.

Bilateral Femoral Neck Insufficiency Fractures after Use of a Long-term Anti-resorptive Drug Therapy for Osteoporosis: A Case Report / 대한고관절학회지

A 78-year-old woman developed an insufficiency fracture on her right femoral neck without trauma after four years of treatment with a bisphosphonate. Her fracture was fixed by two screws and her anti-osteoporotic drug was changed from an anti-resorptive to an anabolic agent. Seven months later, however, she sustained similar insufficiency fracture on the left femoral neck and was treated with the same method. She developed right inguinal pain again approximately eight months after her right side operation. The results of imaging tests revealed that her insufficiency fracture was converted to complete fracture, and that the fracture gap had widened as well. Her right hip was revised with hemiarthroplasty. A histological exam of the fracture site revealed evidence of decreased bone healing. Long-term administration of anti-resorptive drug prevents bone healing and remodeling and can result in atypical fractures of the femoral neck. Osteosynthesis was difficult to accomplish despite the application of proactive fixation. Therefore, more rigid fixation and careful postoperative treatment should be considered.

Particular Features of Surgical Site Infection in Posterior Lumbar Interbody Fusion

BACKGROUND: Previous reports have observed differences only in infection rates between posterolateral fusion and posterior lumbar interbody fusion (PLIF). There have been no reports that describe the particular features of surgical site infection (SSI) in PLIF. In this study, we endeavor to identify the distinguishing characteristics and risk factors of SSI in PLIF. METHODS: Our study undertook a review of a case series of an institute. Patients who had undergone PLIF consecutively in the author's hospital were reviewed. Two proactive procedures were introduced during the study period. One was irrigation of the autolocal bone, and the other was the intradiscal space irrigation with a nozzle. Infection rate and risk factors were analyzed. For subgroup analysis, the elapsed time to a diagnosis (ETD), clinical manifestations, hematologic findings, and causative bacteria were examined in patients with SSI. RESULTS: In a total of 1,831 cases, there were 30 cases of SSI (1.6%). Long operation time was an independent risk factor (p = 0.008), and local bone irrigation was an independent protective factor (p = 0.001). Two cases of referred SSI were included in the subgroup analysis. There were 6/32 (19%) superficial incisional infections (SII), 6/32 (19%) deep incisional infections (DII), and 20/32 (62%) organ/space infections (O/SI). The difference of incidence among three groups was significant (p = 0.002).The most common bacteria encountered were methicillin-resistant Staphylococcus epidermidis followed by methicillin-resistant S. aureus in incisional infections, and no growth followed by S. epidermidis in O/SI. ETD was 8.5 +/- 2.3 days in SII, 8.7 +/- 2.3 days in DII and 164.5 +/- 131.1 days in O/SI (p = 0.013). CONCLUSIONS: The rate of SSI in PLIF was 1.6%, with the most common type being O/SI. The causative bacteria of O/SI was of lower virulence than in the incisional infection, and thus diagnosis was delayed due to its latent and insidious feature. Contamination of auto-local bone was presumed attributable to the progression of SSI. Irrigation of auto-local bone helped in the reduction of SSI.

Trends in Nursing Research in Korea: Research Trends for Studies Published from the Inaugural Issue to 2010 in the Journal of Korean Academy of Nursing and the Journals Published by Member Societies under Korean Academy of Nursing Science

PURPOSE: The purpose of this study was to identify trends for studies published in the Journal of Korean Academy of Nursing and journals published by member societies from inaugural issues to 2010. METHODS: A total of 6890 studies were analyzed using descriptive statistics. RESULTS: Quantitative studies accounted for 83.6% while qualitative studies accounted for 14.4%. Most frequently used research designs were quasi-experimental (91.1%) for experimental research and survey (85.2%) for non-experimental research. Most frequent study participants were healthy people (35.8%), most frequent nursing interventions, nursing skills (53.5%), and 39.8% used knowledge, attitude and behavior outcomes for dependent variables. Most frequently used keyword was elderly. Survey studies decreased from 1991 to 2010 by approximately 50%, while qualitative studies increased by about 20%. True experimental research (1.2%) showed no significant changes. Studies focusing on healthy populations increased from 2001-2005 (37.5%) to 2006-2010 (41.0%). From 1970 to 2010, studies using questionnaire accounted for over 50% whereas physiological measurement, approximately 5% only. Experimental studies using nursing skill interventions increased from 1970-1980 (30.4%) to 2006-2010 (64.0%). No significant changes were noted in studies using knowledge, attitude and behavior (39.9% ) as dependent variables. CONCLUSION: The results suggest that further expansion of true experimental, qualitative studies and physiological measurements are needed.

Lipofibromatous Hamartoma on the Median nerve: A Case Report / 대한정형외과연구학회지

Lipofibromatous hamartoma is a rare, benign neoplasm of peripheral nerves that usually involved the median nerve. Clinical symptoms are mass, neuropathy, tenderness, muscle atrophy and limitation of range of motion. If the tumor is occurred on the median nerve, secondary carpal tunnel syndrome may be happened. We report a patient with a lipofibromatous hamartoma in the median nerve focusing on clinical symtoms and treatment.

"Delta(Delta) wire Technique" for Bony Mallet Finger: Surgical Technique / 대한정형외과연구학회지

Bony mallet finger is treated by from conservative management to various operative options. A lot of internal fixations except hook plate lead to cartilage damage and limitation of motion of distal interphalangeal joint. Thus we introduce Delta(Delta)-wire technique which can permit early joint motion and give strong compression force on the fracture fragment continuously.

Treatment of Infected Non-union in the Knee with High Tibial Osteotomy State: A Case Report / 대한정형외과연구학회지

High tibial osteotomy is one of established methods in the treatment for medial knee osteoarthritis with varus deformity in younger patients. Infections after high tibial osteotomy are rare. Infection management is difficult, but there is no definitely standardized treatment. We report the case of infection after high tibial osteotomy that was treated clinically and radio-graphically with literature reviews.

Cementless Total Hip Arthroplasty with Fourth Generation Ceramic-on-Ceramic Articulation: Minimum Two Years of Follow-up / 대한고관절학회지

PURPOSE: The purpose of this study is to report clinical and radiographic results over a period of two 2 years after cementless total hip arthroplasty (THA) with fourth generation ceramic-on-ceramic articulation. MATERIALS AND METHODS: We studied 22 patients, 23 cases which were followed up for two years among 25 patients, 26 patients who underwent cementless THA with the fourth generation ceramic between April 2009 and December 2009. The average age of the patients was 55.9 years old(22 to 72 years old), and the average follow-up duration was 28 months(24 to 32 months). A clinical evaluation was performed using the Harris hip score (HHS), and radiologic evaluation was based on acetabular cups and osteolysis of the femoral stems, instability, distance, angle, and so on. RESULTS: HHS showed an increase, from 54 for before-surgical treatment, to 91 at the last follow-up. Inguinal pain was observed in one case, and femoral pain was observed in two cases. Stable fixation was achieved in all cases, and no instability, osteolysis, or movement of acetabular cups and femoral stems was observed. CONCLUSION: Clinical and radiological short-term results for use ofthe fourth generation ceramic-on-ceramic cementless THA have favorable so far. Further follow-up study should be performed for evaluation of the long-term results.

Causes of Femoral Component Radiologic Abnormality After Total Knee Arthroplasty Using Legacy Posterior Stabilized-Flex Prosthesis / 대한정형외과연구학회지

PURPOSE: We analyzed the causative factors of femoral component radiologic abnormality after total knee arthroplasty (TKA) using a Legacy Posterior Stabilized (LPS)-Flex prosthesis. MATERIALS AND METHODS: 140 cases of TKA using LPS-Flex and 140 cases of Vanguard from Jan 2008 to June 2010 were analyzed and radiographic abnormalities around the femoral stems were compared. Secondly, TKA using LPS-Flex was divided into two groups according to the posterior femoral cutting technique, which were single cutting method and additional cutting method. Accuracy of the femoral posterior resection was compared. RESULTS: Radiographically, anterior radiolucent line was found in eight cases with LPS-Flex but no case with Vanguard. Posterior overhang more than 30% was found in ten cases in both groups. Posterior bone defect more than 50% was found in 23 and seven cases respectively. Anterior radiolucent line and posterior bone defect were observed significantly more in LPS-Flex. In the second study, we found femoral posterior bone defect in 20 cases with additional cutting method which was caused by flexion of the femoral box-cutting guide. CONCLUSION: Posterior bone defect from LPS-Flex was caused by inappropriate resection due to flexion of the box cutting guide. Single cutting method should be adopted for more accurate posterior femoral cutting.

Study on the Removal of Segmentally Broken Interlocking Screw in Intramedullary Nail / 대한정형외과연구학회지

In the literature, it is extremely difficult and takes long time to remove middle part of segmentally broken screws using ball-tip guide and extraction hook after femoral interlocking intramedullary nailing. Proximal part of broken locked screw can be removed with screwdriver easily, but it is very difficult to remove distal and especially middle part of broken screw which are usually angulated and should be removed to avoid interference with further procedure and complications. So we designed a technique for removal of segmentally broken distal locked screw which can be removed after withdrawal of nail proximally to realign screw segments and then actually applied this method to real case with short operative time and satisfactory outcome.

The Oblique Proximal Interlocking Screw for Intramedullary Nailing Proximal Tibial Fractures: Is It Safe? / 대한정형외과학회잡지

PURPOSE: We tried to reveal radiographic clues for the possibility of damages to the important structures, including the peroneal nerve and the anterior tibial artery, caused by a proximal interlocking screw with a medial to lateral oblique direction (ObML-PIS). MATERIALS AND METHODS: The length of the proximal tibiofiular joint (PTFJ) was measured from the tip of the fibular head to the end of PTFJ on the simple oblique radiographs of 22 cases of tibial intramedullary (IM) nailing. The center (O) of the IM nailing, from the tibial anterior cortex at the level of insertion of an ObML-PIS, was measured on the simple lateral radiographs. The angle POA (P: a point 10 mm anterior from the anterior fibular border, A: a point on the tangent line from the O point to the posteromedial cortex of the fibula) was measured on the MR axial view of 60 cases, and within this angle an ObML-PIS could injure the important anatomical structures. Transverse and 45-degree oblique diameters of the proximal tibia on the MR axial view were also measured. RESULTS: The PTFJ length was 18.5+/-3.3 mm and the O point was located at 15.3+/-3.4 mm posterior from the tibial anterior cortex. The angle POA was 21.4+/-6.2-67.8+/-6.7 degrees with medial to lateral oblique directions. The transverse diameter of the proximal tibia was 58.0+/-5.8 mm and the 45-degree oblique diameter was 50.7+/-6.2 mm. CONCLUSION: Special caution may be needed when we use an ObML-PIS because it is located at the level distal from the end of the PTFJ and within the POA angle, and the peroneal nerve and anterior tibial artery can possibly be severed.

Reconsideration of decision making for third molar extraction

INTRODUCTION: Third molar extraction is one of the most common procedures in oral and maxillofacial surgery. The impacted third molar causes many pathological conditions, such as pericoronitis, caries, periodontitis, resorption of adjacent teeth, and cyst or tumors associated with impacted teeth. Extraction is often considered the treatment of choice for impacted lower third molars. On the other hand, imprudent extraction of deeply impacted third molars can cause permanent complications, such as inferior alveolar nerve damage. Therefore, guidelines for the extraction of lower third molars should be set to prevent embarrassing complications. This study examined the indication and current trends of the extracted lower third molars in the dental hospital of a dental college. MATERIALS AND METHODS: 557 extracted third molars were evaluated at the department of oral and maxillofacial surgery of Yonsei University. The chief complaint, diagnosis, age and degree of impaction were analyzed to determine the tendency for the extraction of asymptomatic lower third molars. RESULTS: The percentage of asymptomatic third molars was 40.8%. In cases of full impacted tooth or full erupted tooth, the percentage of asymptomatic teeth was more than 50% (52.4% and 54.3, respectively). Among those partially impacted teeth, 73.1% of them showed symptoms, such as pain, tenderness and swelling. In terms of age, pericoronitis was evident at a younger age, and dental caries/periodontitis was the main cause of removal in those aged over 50. Twenty nine cases (1.6%) had teeth associated with pathological changes. CONCLUSION: The incidence of pathological changes to the lower third molar was relatively low. Surgical extraction is recommended in cases of partially impacted teeth. In Korea, the incidence of asymptomatic third molar extraction was relatively higher than in European countries. More careful attention would be desirable to consider the risks and benefits of lower third molar extraction.